About this item Polycarbonate Made in USA and Imported Medical Air Mattress: Active mattress replacement system provides both alternating pressure and low air loss to optimize pressure redistribution, shear/friction reduction, and microclimate control 20 Individual Cells: Air bed system includes 20 individually replaceable 8-inch air bladders to maximize immersion and envelopment; includes pillow feature for head stability and comfort Durable Material: Alternating pressure mattress features removable 4-way stretch PU cover is fluid resistant, low shear and vapor permeable, helping protect the skin from friction and moisture Audio and Visual Alarm: Automatically alerts when air pressure is low