Proactive Protekt Gel Overlay. Optimal overlay surface for the prevention and treatment of pressure ulcers. Convoluted high density polyurethane foam top layer. 15 horizontal gel bladders prevents migration and bottoming out. Gel bladders contain an aqueous gel composition that provides deep immersion. Base foundation is a high density/high resilient foam construction which prevents bottoming out. Nylon top cover is fluid resistant, vapor permeable and anti-microbial/anti-bacterial.Bottom vinyl cover has 4 elastic corner straps that secures overlay to the mattress. Gel maintains room temperature at all times.