The Britax Aspen Base allows you to install your Infant Car Seat confidently every time. ClickTight Installation is secure and struggle-free, whether using the vehicle seat belt or lower connectors. Level indicators and spring-assist recline make it quick and easy to find the correct angle. Specifications Install with Confidence, Every Time. Features ClickTight technology for a secure installation without the struggle. Level indicators and spring-assist recline make finding your vehicle's installation angle easy. SpaceSaver Design, Slim outside, spacious inside! Frees up backseat space while giving your child plenty of room for the ride. An additional base is perfect for quick in and outs for multi-car families. Suitable for children 4 to 30 lbs.