Comparison Casio A-159WA-N1 vs Casio B640WD-1A

A caliber can be described as the type of movement used in a watch. It is expensive and impractical to design a unique movement for each watch model, so most manufacturers often use the same movement in different watch models, sometimes with significantly different designs. The term "caliber" is due to the fact that initially the type of movement was designated by a number (in inch lines) corresponding to its largest size; however, today unique names or alphanumeric indices that are not directly related to sizes are widely used.

Knowing the name of the caliber on which the watch you are interested in is built, you can, if desired, find more detailed information about the mechanism and determine how its characteristics meet your requirements.

The shape of the watch case; most often the dial has the same shape, but there are exceptions (for example, a rectangular display in a round case).

This parameter practically does not affect the functionality, so the choice in this case is related solely to how convenient and pleasant-looking one or another option is for you. Also, shape data can be useful if the watch is chosen as a fashion accessory that plays a well-defined role in the image being created. As for specific options, round cases are the most common nowadays — they are easy to manufacture, look neat and fit almost any style of watch. Rectangular watches are also quite popular, they can also belong to different styles; however, such cases are more bulky than round cases, and therefore are used less frequently. The square shape is actually a variation of the rectangular shape. Oval is considered to be suitable primarily for women's watches, although there are also single men's models with such cases. There are other types of cases — polygonal, barrel-shaped, as well as products in non-standard design.

A mechanism that allows you to quickly change the length of the bracelet without disassembling it or using additional devices. Usually performed in the form of a miniature screw, by turning which, you can adjust the length; the range of such adjustment is most often of the order of 10 – 15 mm.

Such a mechanism is relevant primarily for watches with a clip-on clasp (see the relevant paragraph). With traditional adjustment, the clasp has to be disassembled, which requires both tools and certain skills. The quick extension system, in turn, is extremely easy to use and is available even in a complete "separation from civilization" — for example, in nature.

As the name suggests, this parameter determines the degree of resistance of the watch to moisture. It is traditionally stated as the maximum depth under water at which the watch is able to remain watertight; however, it must be borne in mind that this number is very arbitrary. The fact is that when calculating the maximum immersion depth, only the static pressure of water is taken into account, that is, the pressure at complete immobility; at the same time, any movement creates dynamic pressure, which significantly increases the load on the body. In practice, this means that a mark of, for example, 50 m does not mean that you can dive to a depth of 50 m with a watch.

Modern water protection markings correspond to the following practical possibilities:

— 30 m(same as “Water Resistant” without any numbers). Entry level, drops of water are allowed, but not strong splashes. For example, such a watch can be left on in the rain or when washing, but when showering or washing a car, it should be left in a safe place. Of course, there is no talk of immersion in water.

- 50 m. Minimum water resistance, allowing the watch to be immersed in water. These watches can usually be used for swimming, and in some cases even jumping into the water (but not from towers), but they are not suitable for more serious tasks like surfing, snorkeling or scuba diving. As a rule, buttons are not allowed to be...used underwater.

- 100 m. This degree of water protection allows not only swimming, but also diving to shallow depths, however, it is still considered insufficient for surfing, jumping from towers and scuba diving.

- 200 m. Watches with such water protection are classified as “divers”; models and can withstand scuba diving to depths of up to 20 m.

- 300 m or more. Professional diving models suitable for diving to significant depths.

Please note that the characteristics described are approximate. Specific indicators of water resistance and the possibility of using the watch with water should be clarified according to the official data of the manufacturer.

The nominal size of a watch case in diameter (for round cases) or width (for other options, see "Case Shape"). In the most miniature modern models, this size is 21 – 25 mm or even less, among the largest there are cases of 46 – 50 mm and even larger.

Larger watches are more convenient in the sense that the dial readings are better visible on them, and it is easier to provide various additional functions in the design. On the other hand, small watches look neater and create less discomfort directly when worn. In addition, female models (see "Gender") are traditionally made more miniature than male ones. So the choice for this indicator depends mainly on the intended specifics of the application: for example, large cases are best suited for outdoor activities and tourism, about 41 – 45 mm in size, for household wear (regardless of gender) — about 31 – 35 mm, and as an accessory to an evening dress, a small watch of 30 mm or less would be more appropriate.

Also note that the size of a compatible strap/bracelet is associated with this indicator — see "Strap Width" for details.

The thickness of the watch case. A fairly obvious parameter; we only note that nowadays it is customary to attribute watches with a thickness of less than 7 mm to ultra-thin models. This design has both aesthetic and quite practical meaning — a thin watch will be useful for those who wear narrow sleeves with tight-fitting cuffs.

Total weight of the watch. As a rule, it is indicated taking into account the complete strap/bracelet.

The lightest modern watch weighs no more than 50 g. The most popular models weigh 50 - 100 g, and weight more than 150 g most often means not only a large, but also a fairly advanced device, usually for sports and tourism purposes.

Both light and heavy weight have their advantages: light watches create minimal inconvenience when worn, while massive watches are subconsciously perceived as a solid and reliable device.