The Britax Seat Saver Waterproof Liner is designed with deep sides to fit securely into the seating area of your car seat to contain liquids and crumbs and keep your car seat clean. Perfect to protect from diaper leaks, potty training accidents, and wet bathing suits, the waterproof design is made out of EZ-Dry wicking fabric to pull moisture away from your child and keep the seating area dry and comfortable.