Premium water mattress features 25 mil vinyl (25% thicker than most), Deep molded Feathertop pressure reduction surface for greatest conforming comfort, lumbar support with 2-5-2 fiber layer waveless system - tethered to corners to prevent shifting, heater compatible bottom, bottom seams for greater durability, reinforced corners. Fits standard wood type waterbed frames 60x84-inch ID. If you dont already have a frame, frame building instructions included. Made in USA. 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. Our 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 water-mattresses go a step further with our unique deep molded Feathertop pressure reduction surface. Our Feathertop surface relives surface tension and further reduces pressures to allow for true flotation sleep so your muscles and body 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 rave about the health benefits and how well they sleep on Strobel Waterbeds. Made in USA.