Its high density foam construction prevents depression damage that is caused by car seats the bottom tray keeps all cars seats level and in proper position and the kick plate protects upholstery from shoe scuffs works with all isofix compatible car seat systems and fits all cars the two stage seat saver will fit the various car seats that you child requires stage 1 bottom tray is used alone with rear facing infant seats stage 2 add the back part of the seat saver for front facing and