Invacare microAIR MA55 Alternating Pressure Mattress with On-Demand Low Air Loss buy now. The Invacare® microAIR® MA55 mattress ensures patient comfort by circulating air, preventing pressure ulcers with its alternating pressure design and 16 bladders. It maintains a cool, dry environment with on-demand low air loss and offers customizable therapy cycles. Safety features include constant pressure monitoring, audio-visual alarms, and a system lockout button. The mattress cover is antimicrobial and fluid-proof. With a 10 LPM compressor, it provides efficient operation and safety during power outages.