DMI's Convoluted Wheelchair Foam Seat Pad Cushion helps relieve pressure and is ideal for the prevention and treatment of decubitus ulcers. The pressure relief cushion for wheelchairs has a convoluted surface that helps with weight distribution and air circulation. This chair accessories cushion provides comfort and support for those who have so sit for long periods of time. It is made of medical-grade foam for long lasting use. Chair seat cushion pad measures 16" x 18" x 4". Plaid.