The Invacare MNS400 is a full-depth (8") powered alternating pressure air mattress replacement system which reduces interface pressure for the treatment of Stage I to Stage IV pressure ulcers. The MNS400 reduces interface pressures below capillary closure by alternating pressure in the 8-inch air cell bladders every 5, 10 or 15 minutes. The power unit control combines simplified operations with effecitve results.