Safety is the most important thing when it comes to a child car seat. This is the area where we think and refine with passion and a constant drive for improvement. The results are tested by competent experts in leading laboratories around the world. Strictly and without compromise.
The result: an ADAC safety rating of 1.9 (test May 2019), certification to UN ECE R44/04 and now also UN ECE R129/4, plus TÜV approval for use in aircraft. That makes it one of the safest child car seats worldwide.
Certified and tested according to UNECE
ECE R44/04
Certified and tested by TÜV SÜD
Our principle is to improve what already exists, incorporate new ideas and technologies, and develop innovative safety concepts from them. For example, you can use the nachfolger HyFive (Hy5) over a longer period of time. To do that, we combined an infant carrier with a child seat—without compromising on safety.
On top of that comes the SAS technology we developed, which—together with its exceptional design—makes it a distinctive game changer for travel. In other words: we’re very proud to have created something that questions, or even surpasses, everything that came before.
HyFive features a permanent Air Control System (ACS) and a Side-Air-Suspension (SAS) system, which together make up the smart part of the seat.
Safety Center
This is the guarantee that the child car seat complies with legal requirements. The UN ECE approval for our seats includes, among other things, front impact, rear impact, and rollover tests. The HyFive (HY5) was also tested for use with a lap belt only.
The current European standard is UN ECE R129, which we passed with the nachfolger HyFive CITY R129 (without any technical modifications). Since 2025, we are therefore allowed to market the seat again in the EU without restrictions.
The nachfolger HyFive WORLD and the HyFive CITY (until 2024), as well as older models such as the HY5 and the HY5.1TT, are still approved under UN ECE R44/04 and may continue to be used worldwide (including in the EU) without restrictions.
From September 2024, placing UN ECE R44 seats on the market was prohibited. This means these R44 seats are still absolutely safe, but you can no longer buy them new in the EU. They can still be offered through rental services, for example—this can happen and is permitted. When used, the seats continue to comply with today’s applicable standards.
HyFive CITY is approved under UN ECE R129 for the ISO/R3 category in almost all vehicles (previously even UNIVERSAL under UN ECE R44/04) and is labeled with the corresponding approval tag. This means the HyFive CITY child car seat can be used in all vehicles that are equipped with a 3-point belt or lap belt and are listed in the current vehicle list. Installation using a lap belt is primarily for use in aircraft, buses, or trains, but it is also intended for vehicles that are older or have been converted for travel. The connection via Top Tether is important, but only required for vehicles in category M1, i.e., normal passenger cars. In aircraft, trucks, buses, or on trains, you don’t need a Top Tether. If a car is not on the vehicle list, we’ll be happy to check it for you on a case-by-case basis. But we can already say that this is only an issue with very, very sporty vehicles (Ferraris, Porsche GT3, Audi RS models—basically vehicles with deep bucket seats). In normal family-friendly vehicles, there is absolutely no problem. We also appreciate your feedback on installation, and we’re happy to add your car to the list so other parents have better guidance.
The SAS system was originally developed for the German ADAC sled test and is now also mandatory for UN ECE R129. It delivers excellent side-crash results and prevents serious head injuries. Children’s heads need special protection because this is probably the most sensitive and vulnerable area in small children. Additional attachments are unnecessary with HyFive and its side airbags, and this also means three seats fit side by side on the rear bench—even in compact cars.
The three-point belt system offers maximum safety for your child and makes buckling up quick and easy. HyFive is also approved for installation with a lap belt, which makes it possible to use it on an aircraft, on a bus, or on a train.
HyFive is installed easily using the vehicle seat belt and the Top Tether strap (if available).
The additional tether strap, also called the Top Tether, is located at the top of the child seat. It reduces forward head movement in a frontal crash. There is no Top Tether anchor point on buses, trains, or aircraft, and using the Top Tether is not necessary there.
The safest place for children in the car is behind the front seats. The belt routing must match the child seat. A full vehicle seat with a three-point belt system is required. The seat can be installed on the front passenger seat, but the passenger airbag must be switched off.
Note: Please check the vehicle manual and the vehicle list before buying a child seat.
Checklist:
Checklist:
You can also have a look at the nachfolger® kids car seats at one of our dealers:
