Alternating pressure relief system is specifically designed for the treatment of stage I and II pressure sores, and for prevention. Air pump cycles varying pressures over a period of 8 or nine minutes through cells of vinyl mattress for relief of pressure points. Control knob adjusts comfort range in 8 levels. Features patented air compressor chamber with ultra-quiet operation, external air filter intake, and securing straps on the mattress. Latex-free. Specifications: • Bubble style pad effectively reduces pressure• Automatic 5-minute cycle alternately inflates and deflates• Heavy gauge, medical grade vinyl is easy to clean, flame retardant and anti-bacterial• Pump mounts to bed with built-in mounting bracket and features an illuminated on/off switch• Available with standard fixed pressure pump or deluxe variable pressure pump• 78" x 34" x 2 ½"• 275 lb maximum weight capacity• Latex Free