The Alpha Active 3 pressure redistribution mattress overlay system has been specially designed to prevent pressure ulcers for patients who cannot be frequently repositioned, are in rehabilitation, or who cannot tolerate a moving surface. The mattress overlay system benefits from a reactive/static mode, which equalizes the cell pressure to redistribute the body weight over a larger surface area. It also features an active/alternating mode where it periodically redistributes pressure away from vulnerable areas by inflating and deflating the cells alternately underneath the patient. The ergonomically designed Alpha Active 3 has a modular composition which enables easy maintenance and cleaning, increased comfort in the head section, variable pressure control settings and a compact and quiet pump.