The CYBEX Base 2 is for use with the CYBEX Aton 2 Infant Car Seat. An additional base is ideal for multi-car families, allowing you to conveniently switch between cars by easily attaching the Aton 2 to the pre-installed car seat base. The height adjustable load leg stabilizes the car seat and can reduce crash forces by up to 40% by transferring impact energy to the vehicle's floor. Date of manufacture : 2019 Date of expiration : 2025