The Trekker 25 is perfect for those wanting true four season performance & a comfortable nights sleep, its low weight & excellent pack size make it perfect for trekking & back packing. This reliable mat has a high quality PU foam core that expands when the valve is opened to draw air into the mat making it fully self inflating. You can of course speed up inflation, or top it up, by mouth. The mat is covered with a tough 150D rip stop polyester that has a tough TPU membrane on the inside to make it completely airtight. This mat is supplied with a stuff sack, repair kit & retaining straps. TPU membrane for air-tight seal Quality lightweight vertically drilled 20kg/m 3 PU foam core for lasting performance & full inflation 150D rip-stop polyester top & base fabric Mat supplied with stuff sack matching upper fabric retaining bands & repair kit