High-profile backrest provides your lower back with the support and comfort it deserves. With high-density, medical-grade, antiallergenic foam, this backrest keeps its shape to keep you comfortable for long periods of time. The elastic strap adjusts to fit any chair and holds the backrest firmly and securely in place. The full-size zipper provides easy access to the removable and machine-washable cover. Cover is made of 100 percent polyester velour.