Premium water-mattress features a patented Double-Wall System for added peace of mind, 25 mil vinyl (25% thicker than most), deep moulded feather top pressure reduction surface for greatest conforming comfort, lumbar support with 9-12-9 fibre layer waveless system. Fits standard wood type waterbed frames. If you don't have a frame, frame building instructions included. Strobel Waterbeds are naturally fire resistant and do not require flame retardant chemical based flame barriers like other mattresses to comply with federal fire safety regulations. These bodies are over 90% water. Strobel Waterbeds achieve nearly zero-gravity. Archimedes' Principle proved a body floating or submerged in a liquid is buoyed up by a force equal to the weight of the liquid displaced, thus the human body loses the amount of weight of the liquid displaced so that your body is lightened. This imposes less pressure on the body. Strobel Waterbeds go a step further with unique deep moulded ''feather top'' pressure reduction surface. The feather top surface relieves surface tension and further reduces pressures to allow for true flotation sleep so your muscles can truly relax. Strobel Hydro-Support water-mattresses also feature reinforced corners, 4-way tethered waveless system to prevent shifting, bottom seams to relieve pressure on seams, thermally efficient heater compatible bottoms, and added lumbar support for better back support. Many people talk about the health benefits and how well they sleep on Strobel Waterbeds. Made in USA.