Flat support cushions provide some relief, but can't give you target support where you need it most - your lower back. Taking the pressure off and helping you sit properly. The flat part lies flush against the back of your seat. Slip this lumbar support cushion on any chair or seat for instant, ergonomic positioning and posture correction. The premium, high-density memory foam molds to your shape for not too firm, not too soft support that lasts long. It's designed to fit most standard chairs and car seats.