Before being launched on the market, each product goes through a validation process carried out by certified laboratories that guarantee that such car seat meets the parameters laid down by the law. Being certified means that the item complies with the safety requirements expressed in the United Nations Economic Commission for Europe (UNECE) regulations. There are baby car seats on sale validated by two different regulations: R44 is the oldest regulation and it certifies cars seats per weight with certification number starting with 04, that is, the more recent version of the regulation in force. Most can be installed using the the 3-point safety belt, but there are other seats that are installed using the Isofix system. Baby car seats are usually certified for use from birth up to 13 Kg. Systems approved by the R44 regulation can still be used as they are an important solution for vehicles with no Isofix system. Once installed and used correctly, they provide a good safety level. The R129 is the more recent regulation, also known as i-Size - the updated R44. In this case, car seats are certified by height and not by weight. The R129's main benefits are that it is easier to choose and swap car seats, make decisions on what direction they face, and how they are installed. Introducing height as reference (instead of weight groups that overlap) and not allowing front-facing transport of babies before the age of 15 months are some of the points that make it easier for families to choose a baby car seat and they also ensure that fewer mistakes are made when using it. Also, introducing requirements for lateral impact, which had been non-existent, means further protection and safety. In its first phase, the R129 was only applicable to car seats with their own in-built belt for Isofix installation. However, some car seat brands are certified from birth up to 75 or 87 cm which can be installed with the Isofix system (usually with a base) or with the 3-point car seat belt. Such versatility means that the baby car seat can be used in different vehicles, with or without Isofix, as both systems are safe when the installation instructions are followed carefully.