The Base One is compatible with the Aton S2 i-Size and the Aton B2 i-Size. Equipped with individually rotatable ISOFIX connectors and a height-adjustable load leg, the Base One adds extra safety and stability to these infant car seats. One-click installation makes it safe and simple to take your car seat in and out of your vehicle, with no further fastening required. Installation indicators also help you get the base set up successfully, letting you know when it’s safe and ready to use.