4 four way stretch cover material prevents slippage and friction. Waterfall skirt seals moisture out. Welded and taped seams aid in infection control. High Temperature Stability to deliver consistent immersion, performance and comfort YKK zipper: World’s best Japanese zippers. YKK adopts the self-locking puller technology in the zippers, which makes it easy to pull and lock without slipping. This design enables you to move around and your zipper will always stay in place. After being used for decades, YKK zipper still keeps its excellent condition in both appearance and functionality. With self-lubrication, YKK zippers move even more smoothly the more you use them. Visco-elastic/memory foam cell structure provides low-shear surface. Hospital grade, designed to perform within high humidity conditions. Protects the patient against bottoming out in sacral region. Provides excellent anatomical support. Provides protection against ‘bottoming-out’ during transfer, repositioning and whilst in the inclined/fowler position. Provides exceptional comfort, support for repositioning and patient care.