The AccuMax Quantum VPC Surface has been specifically designed to prevent an occurrence of pressure ulcers in patients who are moderately susceptible to skin breakdown. Rather than relying on a pump, blower, or power source to redistribute pressure in response to patient movement, the AccuMax Quantum features a Controlled release valve Technology which automatically adjusts in response to patient movement, thereby providing consistent pressure redistribution during a therapy session. The Viscoelastic foam topper provides an even greater degree of comfort. The unit as a whole weighs only 29 pounds, but will support a weight of up to 500 pounds.