United States Watermattress Made In The USA 2 Layer Hardside Watermattress Features: Overcut mattresses - to release pressure on the seams L-corner construction Seam on the bottom of mattress - recessed 2 inches Trimilate Dura Heat black bottom for heat transfer 2 1/2 inch reinforced corners Heavy Duty black waterbed vinyl Fiber is 1.2 oz of Dupont fiber per layer Lifetime Limited Warranty