Skil Care Contour Pressure Relief Seat Cushion Options:w Visco Foam Pad and LSII Cover 20"W x 16"D x 4"H ideal for government and tactical Jorgensen Labs Amber Plastic ideal for government and tactical procurement requirements Durable Construction: Built from high strength light alloy to withstand the rigors of industrial environments and heavy duty cycles The Skil Care Contour Cushion provides further comfort and relief for the tailbone by adding a separate section in the rear with your choice of visco elastic memory foam or a water based gel pod for additional pressure relief in the critical coccyx area Maintains pelvic neutrality to control sliding