If the base of your car seat dips and sags it's probably giiving you constant discomfort when driving. The seat topper fills the sagging gap and allows you to sit in comfort with better posture. It is tapered along the front edge to sit neatly in the well of your car seat. The seat topper is made of high quality comfort foam with a solid wooden base, and is upholstered in attractive hardwearing velour material.