The iCare 5cm Pressure Mattress Overlay is designed to provide added pressure relief and comfort on an existing mattress. These overlays are heat and pressure sensitive causing them to soften around pressure points and inflamed areas. The overlay features ActiveX™ material as its main comfort layer. ActiveX™ is a high grade of elastic type foam which is responsive to temperature around inflamed areas. ActiveX™ will become softer as it becomes warmer. So, around a pressure point it will always soften and allow the blood to circulate freely. They are available in Long Single, King Single, Double and Queen sizes.