Polypropelene SUPERIOR PERFORMANCE vs alternating pressure pad overlays. With an industry leading depth-of-immersion of 3.5 inches, the Prodigy will NEVER BOTTOM OUT the MOST critical factor in pressure sore prevention, pain management and wound healing. Alternating pressure pads typically only provide a 1.5 depth-of-immersion which results in bottoming out - rendering them virtually useless. This is the main reason hospitals and nursing homes NEVER USE BUDGET-PRICED ALTERNATING PRESSURE PAD OVERLAYS. 3-IN-1 FUNCTIONALITY WITH ZONED SETTINGS- The Prodigy provides professional-grade Pressure Sore Prevention, Wound Healing AND Pain Relief-all in 1 product. With 3 zones that can be customized based on the users needs, the Prodigy can be set up for OPTIMIZED comfort and healing.