The Summit 25/38XL Self Inflating Mat from Multimat is the largest mat in the expedition range that has been designed to offer an incredibly comfortable & reliable mat at altitude & in season 5 conditions The Summit 25/38XL has a light weight rip stop nylon upper fabric with water repellent coating on the top & a non-slip water repellent coating base layer to keep it both dry & warm This five season mat offers a unique wedge profile & warm zone for extra comfort & to offer you the highest level of comfort when you most need to rest & recoup before a long hard day of exhilarating expedition The finest top quality foam core is both vertically & horizontally drilled to shed every spare ounce of weight while maintaining lasting performance & full & fast inflation through a Superfast valve so you can set up or break camp quickly which makes this a fantastic choice of mat to either use on its own or as part of a layering system for high altitude & unsupported expeditions