DMI Wheelchair Cushion with Cover. Effortlessly increase your support, comfort, and height in your wheelchair with our DMI Wheelchair Cushion. Our seat cushion is great for wheelchairs, car seats, regular chairs, office chairs, hard benches, and more. Benefits of our cushion include reducing and preventing back stiffness and pain, added comfort to uncomfortable wheelchairs, and the cushion is lightweight and easily portable for travel! Features: Made of lightweight, high density foam that won't crack or crumble, and contains a removable and machine washable cover. Specifications: 3 x 16 x 18 inches, made of poly cotton, navy blue, high density foam.