Comparison Xiaomi Mi Band 4 vs Xiaomi Hey Plus

The primary way to connect a wrist gadget with external devices. For smartwatches and fitness bands (see "Type"), it is assumed to be connected to a smartphone or tablet, while in the case of watch-phones, it's usually about headsets.

— Bluetooth. A wireless technology for direct communication between various devices. There are different versions that indicate the device's capabilities.

• — 5.0. The fifth generation of Bluetooth was released in 2016. The key innovation in version 5.0 was expanding the capabilities related to the "Internet of Things." For example, the Bluetooth Low Energy protocol introduced the ability to double data transfer speed (up to 2 Mbps) at the cost of reducing range, as well as quadruple the range at the cost of reducing speed; additionally, several improvements were introduced concerning simultaneous operation with a large number of connected devices.
• — v 5.1. An update of the version v 5.0 described above. In addition to general improvements in connection quality and reliability, this update implemented an interesting feature such as determining the direction from which the Bluetooth signal comes. This makes it possible to determine the location of connected devices with centimeter accuracy.
• — v 5.2. The update following 5.1 of the fifth-generation Bluetooth. The main innovations in this version included several security improvements, additional optimization of power consumption in LE mode, and a new audio signal format for synchronizing parallel playback on multiple devices.
• — v 5.3.... The Bluetooth v 5.3 wireless communication protocol was introduced in early 2022. Innovations included speeding up the process of coordinating the communication channel between the controller and the device, implementing a feature for rapid switching between low-duty cycle and high-speed modes, improved bandwidth and connection stability by reducing susceptibility to interference. In the event of unexpected interference in Low Energy mode, the procedure for selecting a communication channel for switching is sped up. There were no fundamental innovations in protocol 5.3; however, it is evident that there are several qualitative improvements.
• — v 5.4. The standard generation approved in 2023, which became an intermediate step before Bluetooth 6. The main innovation was the introduction of the PAwR (Periodic Advertising with Responses) mode, allowing watches and other devices to exchange data in large sensor networks with minimal power consumption. Also added was the Encrypted Advertising Data mechanism, enhancing protection against eavesdropping and packet forgery, which is important when using watches for contactless keys or payments. Compared to earlier versions 5.2 and 5.3, Bluetooth 5.4 focuses on security, energy efficiency, and operation in a "noisy" radio environment. In real-world use, this is manifested in more stable data transmission from sensors (heart rate, steps, sleep), battery savings with constant phone connection, and the reliability of functions like notifications or fitness tracking even with many connected devices around.
• — v 6.0. Bluetooth 6 has been officially approved by Bluetooth SIG and offers a number of significant benefits in smartwatches compared to version 5.4. Thanks to the improved Channel Sounding system and LE Audio optimization, such devices maintain connections faster and more stably, determine the distance to the smartphone more accurately (to centimeters), lose frames less frequently during calls or Auracast broadcasts, and provide longer battery life. In practice, this manifests in functions like unlocking a laptop upon approach, precise indoor watch search, reliable operation of heart rate sensors and sports sensors, as well as stable calls even in crowded gyms.
  
  Naturally, to utilize all the capabilities of a particular Bluetooth version, it must be supported not only by the gadget itself but also by the smartphone/tablet to which it is connected.

The material from which the transparent cover of the display is made.

— Plastic. Inexpensive, moreover, quite durable and impact-resistant material: even with a strong impact, the plastic is more likely to crack than crumble into fragments. At the same time, scratches easily appear on such a surface, and over time it inevitably becomes cloudy. Because of this, plastic is found predominantly in inexpensive wearable gadgets.

— Glass. In this case, it can mean both classic silicate glass (the same as, for example, in windows), and some original types of impact-resistant glass that are not related to Gorilla Glass(see below). Regular glass costs more than plastic, but not by much, and it looks better and stays clear longer due to its scratch resistance. The main disadvantages of this material are fragility and a tendency to crumble into sharp fragments upon impact. Impact-resistant glass types are devoid of this drawback to one degree or another, but they are also more expensive. According to the price category of the gadget, you can quite accurately determine what kind of glass it uses — ordinary or shock-resistant.

— Sapphire. The coating made of synthetic sapphire is used exclusively in premium-class gadgets — this is due to the complexity of its production and, accordingly, the high cost. On the practical s...ide, sapphire is extremely scratch resistant (it is only possible to scratch such glass with a diamond or special tools), but at the same time it is fragile and easily breaks from impact.

— Gorilla glass. A family of shock-resistant glass types created by Corning and widely used in modern electronics, including wearable gadgets. In addition to strength, Gorilla Glass is also distinguished by good scratch resistance, while being relatively inexpensive (by the standards of such a coating), which has led to their popularity. However, the specific properties of such glass depend on its version; Here are the options that are relevant for modern wearable devices:

• Gorilla Glass v3. The oldest current version was released in 2013. Nevertheless, even such a coating is noticeably superior to traditional glass (not to mention plastic) in terms of transparency and scratch resistance.
• Gorilla Glass v4. Version released in 2014. A key feature was that the development of this coating focused on impact resistance (whereas previous generations focused mainly on scratch resistance). As a result, the glass turned out to be twice as strong as in version 3, despite the fact that its thickness was only 0.4 mm.
• Gorilla Glass SR+. The first version of Gorilla Glass, designed specifically for smartwatches and other miniature wearable gadgets; presented in 2016. According to the creators, the scratch resistance of such coatings approaches those of sapphire glass while maintaining the main advantages of Gorilla Glass — high strength and transparency. In general, for this material, superiority over "alternative options" is claimed by 70% in terms of strength specs and by 25% in terms of optical properties.
• Gorilla Glass DX. Another type of glass, specially designed for wearable devices. It was released in 2018 at the same time as the DX+ version (see below). Of the key improvements in Gorilla Glass DX, in particular, increased anti-reflective properties and an increase in the contrast level of the visible image by 50% are announced; the latter, among other things, allows you to reduce the actual brightness and, accordingly, the power consumption of screens without compromising image quality, which is especially important for miniature wearable devices. And this material differs from the DX+ type coating, on the one hand, by lower scratch resistance, and, on the other hand, by higher anti-reflective specs.
• Gorilla Glass DX+. Almost the same as the original version of DX, related to the same specialization — wearable wearable gadgets and other miniature devices. At the same time, DX + has a higher scratch resistance, but has slightly worse anti-reflective specs. Otherwise, these types of coverage are almost identical.

The amount of own storage provided in the design of the watch/bracelet. This memory is used for permanent storage of various information: call log, received SMS and other messages, additional applications, data on physical activity for a certain time, etc. The larger its volume, the more data can be stored in the device without the need to clean it to free up space. On the other hand, in the operation of smartwatches, large volumes ( 64 GB, 32 GB, 16 GB, even 8 GB and 4 GB) are not always required, capacious drives are quite expensive, and replaceable cards installed in corresponding slot (see below).

— Built-in player. The presence of a player in the smartwatch allows you to use the gadget to listen to music. There is no need to connect to the phone for this. The songs will play directly from the watch. Therefore, these devices must necessarily have an impressive (as for a watch) amount of storage and be able to connect to headphones (for connection with headphones).

— WiFi. A technology originally used to access the Internet via wireless access points, but more recently also used for direct communication between two devices (such a connection has several advantages over traditional Bluetooth). In wearable gadgets, the first option is most often provided, although the second is also found. However, the specific uses of Wi-Fi may be different depending on the device: accessing websites and various Internet services, remote communication with smart home systems, remote control of digital cameras and other electronics, transmission of the GPS- coordinates via Internet (in children's beacons), etc.

— NFC. Wireless communication technology over short distances (up to 10 cm). The methods of its application, including in wearable devices, may be different. One of the more popular options is using contactless payment (see below); however, the presence of such a function does not hurt to verify separately. Another common fe...ature is the simplification of Bluetooth connection with a smartphone or tablet that also has NFC: instead of manual configuration, it is enough to bring one device to another — and they will automatically establish a connection, all that remains is to confirm it. Other ways of interaction may also be possible, for example, launching a “sports” application on a smartphone when bringing a fitness tracker to it. And theoretically, more specific options for using NFC are also allowed — for example, as a travel pass, ID, etc. Actually, in many models of wearable gadgets, the set of these methods is limited only by installed applications.

— Contactless payment. The possibility of using a wearable gadget for contactless payment. This feature is found only in models with NFC (see above); it actually turns the device into an analogue of a credit card with a chip and allows you to pay without taking the card out of your wallet — just bring your hand with the gadget to the terminal reader. This provides not only additional convenience, but also security. So, bringing the watch to the terminal is definitely easier than reaching into your pocket or purse for a credit card — especially if your hands are busy shopping. And instead of a traditional card, from which an attacker can copy basic details such as a number, CVV code and expiration date (for example, by “peeping” them with the built-in camera), a gadget is used that transmits this data in encrypted form and does not display it explicitly anywhere.
To use contactless payment, usually, you need to synchronize your gadget with your smartphone and set up such payment in the Google Pay or Apple Pay system. But to make payments, a smartphone is no longer required — many wearable devices are able to perform this feature completely autonomously (although this possibility still needs to be specified separately).

— Accelerometer. A sensor that determines the direction of gravity, as well as the accelerations acting on the device. This allows you to track two parameters at once: the current position in space and various physical influences (like tapping or shaking). Most often, the accelerometer is responsible for two main features: automatic rotation of the image on the screen, as well as the operation of the pedometer (in fact, the presence of such a sensor is almost guaranteed to mean the presence of a pedometer, see "Possible measurements"). However, there are other ways to use this sensor — for example, rejecting an incoming call when shaking the watch, turning on the screen when tapping on it, etc.

— Gyroscope. A device that allows you to track the turns of the gadget in one direction or another. Typically used in conjunction with an accelerometer. The gyroscope improves the accuracy of positioning in space (which has a positive effect on the quality of the pedometer and other similar functions), and also provides additional options for managing gestures. However, the specific applications of this sensor are highly dependent on the model.

— Camera. The watch/bracelet has its own built-in camera; its location and purpose differs from model to model. In some devices, the lens is located on the front panel, above the screen, and the matter is limited only to video communication and taking selfies, while others allow you to shoot “classic” photos or videos. At the same time, it is worth noting that anyway, the specs of such cameras are usually very limited — for example, the resolution rarely exceeds 2 megapixels, and autofocus is provided only in the most advanced models.

— Flashlight. Built-in flashlight — usually in the form of a small LED mounted directly in the case. Usually, it has a relatively modest brightness, but it can still be useful for simple tasks like lighting your path at night, lighting in a garage or basement, etc.

The watch supports a certain system of contactless payment for purchases and services through the built-in NFC. See contactless payment for details.

— Apple Pay. "Apple" system of contactless payments, available to owners of the Apple Watch. To use it, you bind a bank card to the device and touch the terminal with your Apple Watch at the stage of paying for purchases or services. The Apple Pay electronic wallet only works with Apple wearable technology.

— Google Wallet. Google Wallet (formerly Google Pay) allows you to pay for purchases using NFC-chip smartwatches based on the Wear OS operating system. The device must have the Google Wallet application installed, and the user will first need to have a supported card of the issuing bank.

— Garmin Pay. A payment service for one-touch payments for purchases using Garmin smartwatches. To pay for goods, you must activate the e-wallet menu on your watch and enter your password from the Garmin Connect Mobile app. After that, it is enough to touch the terminal with your watch at the checkout. In the future, you can make payments without additional entering a password within 24 hours. If you remove your watch from your wrist or turn off the heart rate monitor, you will need to re-enter your password before making a payment.
...> — Samsung Pay. Contactless payment service for purchases and services for smartwatches of the Samsung Gear Watch and Galaxy Watch families. The system is notable for the fact that the Magnetic Secure Transmission (MST) technology introduced by Samsung specialists makes it possible to pay even in terminals without support for contactless payments. Some watches of the South Korean brand can create a magnetic field that imitates a strip of a bank card and transmit information to outdated payment terminals.

The capacity of the battery that is installed in the gadget.

Theoretically, the higher the capacity, the longer the battery can work on a single charge. However, in fact, the battery life of the gadget also depends on its power consumption, and it is determined by the specs of the display and the hardware. Therefore, only models of the same type with very similar specs can be compared in terms of battery capacity; and for an accurate assessment of battery life, it is better to focus on the directly claimed operating time in one mode or another.

It is also worth mentioning that high-capacity batteries inevitably turn out to be quite heavy and bulky. So the capacity of batteries installed in wearable gadgets is also greatly limited by size and weight.

The type of clasp used on a gadget's strap or bracelet.

The most common types of clasps today are the classic buckle, folding clip, folding lock, magnet, snap fastener, and Hook-and-loop. If several options are indicated in the specs at once, it means that the gadget is supplied or can be supplied with different strap options using different types of fasteners. Here is a detailed description of each type:

– Classic (with buckle). Clasp resembling a belt buckle; originally used in traditional wristwatches, but nowadays it has become widespread in smart gadgets. On one half of such a fastener there is a U-shaped or similar frame with a special pin, on the second — a row of holes. When fastening, the second half is threaded through the frame, and the pin is fixed in one of the holes. At the same time, by choosing a particular hole, you can adjust the size of the strap. In addition, the advantages of the classics are reliability, neat appearance and compatibility with many strap materials (with the exception of metal bracelets).

— Clip (unfolding). An option for metal bracelets. The most widespread type of clip, consisting of two curved plates connected by an axis. When unfastened, they open like a book, increasing the overall length of the bracelet and allowing you to easily r...emove the watch from your hand, and when fastened, they fold close to each other and are fixed, securing the bracelet on your wrist. Another, less popular variety is the “butterfly”, which has two flaps that, when opened, rise like wings. In general, the clips are very easy to use, but difficult to set up. They fasten and unfasten with literally one click, but it’s impossible to reconfigure the size of a bracelet with a clip “on the go” — you have to disconnect and reconnect special latches, which requires an additional tool and some skill.

— Magnetic. A fastener in which a strong permanent magnet plays the role of a latch. Such devices are simple and convenient both in use and in adjustment: for fastening and unfastening, it is enough to “stick” or “unstick” a magnet, and size adjustment is carried out right at the time of fastening — by tightening the strap to the desired length. The main disadvantage of such a clasp is that it can only be used with metal bracelets made of magnetic alloys — for example, steel.

— With lock. A clasp that resembles the buckle described above, but has a slightly different principle of operation. On one side of the strap with such a clasp there is a latch pin, on the other side there is a loop of a D-shaped or other shape, as well as a number of holes. When fastening, the side with the pin is threaded into the loop and then fixed in one of the holes; By choosing one or another hole, you can adjust the length of the strap. This design is especially suitable for rubber straps, it is simpler and at the same time more reliable than the buckle, which can also be used with such straps.

— Hook-and-loop. Classic hook-and-loop closure, used exclusively with fabric straps. Like magnetic clasps (see above), such clasps allow you to very accurately adjust the length of the strap right in the process of fastening. Among the disadvantages of Hook-and-loop, in addition to restrictions on the materials of the strap, it is worth noting the tendency to reduce reliability as it wears out. Therefore, nowadays, this type of fastener is quite rare, and is almost never used as the only one available — usually Hook-and-loop is supplemented with another option, for example, a latch.

— Folding lock. Clasp in the form of a detachable lock, the halves of which are on different halves of the bracelet. It is used with finely woven metal bracelets, the so-called "Milanese" ones; at the same time, one half is fixed motionless, and the second can move along its part of the bracelet — in this way the length is adjusted. A tool may be required for adjustment, but the procedure itself is simple — much easier than with clips. And the low prevalence of folding locks is mainly due to the fact that Milanese bracelets are rarely found in smart wearable gadgets.

Wrist coverage suitable for the included watch strap. Usually, the length of the strap can be adjusted, so this paragraph usually indicates not one number, but a range — for example, "130 – 200" (millimetres). If there are several straps in the kit, then several ranges are indicated in the specs, if necessary, with a clarification like “fabric: 115 – 185, metal: 130 – 220” (if the straps are made of different materials).

We emphasize that in this case we are talking not just about the length of the strap, but about the girth of the wrist, for which it is designed. Thus, by measuring your hand in an appropriate way, you can accurately determine whether a particular strap is suitable for a particular person or not. This possibility is especially important if the watch is bought for a user with a non-standard hand size — miniature or, conversely, very large.

In most cases, the weight of the watch body itself is indicated as the weight of the model, since the strap is removable and can be replaced with another one. However, there are also models when the weight is presented with an included strap. Anyway, if the manufacturer indicates a specific method of measuring weight (with or without a strap), we add this information.