Comparison Cybex Sirona Z i-Size vs Cybex Sirona S i-Size

— Seat belt. Installation with the car seat belt. In weight groups 0, 0+ and 1, only the seat is secured in this way; the child's safety is ensured by the seat's own belts. In weight groups 2 and 3, the car belt is used to secure both the seat and the child.

— Tor Tether. An additional harness to increase the security of fixation used in seats with Isofix and Latch systems (see below). One end of the harness is attached to the upper part of the backrest and the other end is attached to a special bracket installed in the floor of the car behind the seat or in the trunk. This reduces the likelihood of the seat being knocked over in a sudden braking or frontal impact and increases the overall safety of the small passenger.

— Support leg. An additional attachment in the form of a support running from the bottom of the seat to the floor of the car. The purpose is similar to the Top Tether described above: it increases the safety of the seat and reduces the risk of the seat toppling when the car comes to a sudden stop. It is most often used with the Isofix system.

— ISOFIX. The installation system for car seats in the weight category up to 18 kg is primarily found in cars from European manufacturers. The seat is secured with two locks in the rear lower part, with optional additional attachments at the top and/or b...ottom. The design ensures foolproof installation, making it nearly impossible to install the seat incorrectly. Isofix requires the car to be equipped with suitable brackets, but even without them, these seats can usually be securely installed using the regular seat belt. However, this option may not be cost-effective, as seats with the Isofix system tend to be relatively expensive.

— LATCH. Installation system similar to Isofix. It is used mainly in American cars and, accordingly, in car seats of American manufacturers. The seat is attached at three points — two at the bottom of the seat and one at the top — so that the seat cannot be installed incorrectly. Like Isofix, seats with Latch also allow fixation with the normal car seat belt.

The presence in the design of the child restraint system of special indicators of correct installation. They help ensure that the child car seat is installed correctly and follows all prescribed safety guidelines. Most often, such indicators are represented by special marks that change color or position when the car seat is installed correctly. Such indicators are placed on Isofix system locks, seat belts for fastening a child, etc. And some models for the youngest passengers have built-in levels or angle indicators that help set the seat in the correct position, facing the rear of the vehicle.

— Isofix base. The product is equipped with a separate Isofix base, which is fixed in the interior of the car on the appropriate fixing clips, and the car seat is installed directly on it. The use of the base provides reliable fixation of the car seat and reduces the risk of its incorrect installation. On the Isofix base are installed mainly car seats of age groups 0+ and 1, some models assume the possibility of placing seats for older kids. It should be noted that car seat models without an Isofix base are also widely available on the market. — Removable cover. Removable car seat cover for cleaning and/or washing. This function is especially useful if the seat is used when feeding a kid.

— Anatomical cushion. Depending on the age group, it can either be a special horseshoe-shaped cushion to support the kid's head (for the youngest ones who are still unable to hold their head on their own), or a special soft headrest that fixes the head from behind and to the sides (for older kids).

— Sun canopy. Plastic (most often) canopy to protect the kid from the sun or bright light.

— Foot cover. A cover that covers the kid's legs and lower body. It is used in seats of age group 0.

— Cup holder. A device used...in car seats to hold a bottle of drink or formula for feeding. Most often done removable.