OVERLAY, GEL PROTEKT EO185 34"X76"X3.5" Convoluted high density polyurethane foam top layer Bladders contain an aqueous gel composition that provides deep submersion Base foundation is a high density high resilient foam construction which prevents bottoming out Cover is a soft nylon urethane coated vapor permeable water proof fabric Top cover is non-shear, low-friction and anti-microbial/bacterial 4 Elastic corner straps secures overlay to mattress Gel maintains room temperature at all times