Best in class gel overlay optimizes pressure redistribution.15 gel bladders cover entire patient contact area for the prevention and treatment of pressure ulcers. Full length “head-to-toe” gel bladders minimize “bottoming out” and “pitting”. New convoluted foam topper vastly improves patient comfort and air circulation. 4 elastic corner straps secure overlay to mattress. Urethane coated nylon cover is water resistant and vapor permeable. Vinyl base is stain resistant and waterproof. Bladders contain an aqueous non-toxic gel and polystyrene beads to minimize gel migration. 34" x 76" x 3.5" 300 lbs weight capacity.