CONFORMAX Anywhere, Anytime Gel Office Seat Cushion (L18) SIZE: 18 Low-profile comfort. Only 1.5 in. thick with  of Ultrasoft viscoelastic Ultragel gel cast directly onto one inch of Ultravis foam guarantees perfect body-conforming fit to the users anatomy ensuring all day, pain free sitting comfort. These durable, handsome removable zippered covers, with conformable top surface and non-slip friction grip bottom ensure maximum comfort while preventing sliding on most surfaces. Covers are water and spill-proof for easy cleaning. Color Black, safe for washing. Air dry recommended. Covers are water and spill-proof for easy cleaning. Color Black, safe for washing. Air dry recommended.