PolyesterImportedGENTLE ON SKIN:The sleeping bag liner is made from soft, lightweight polyester fabric that s breathable and comfortable. The special sanding process makes it even cozier while also preventing problems like pilling, and fading, so it lasts longerPRACTICAL DESIGN:This lightweight travel sheet has a buckle at the top and opens on one side, making it easy to get in and out.Thezipper at the bottom allows for ventilation and foot movement.Unzip the bottom if you feel too warm while sleepingVERSATILE DESIGN:This thermal sleeping bag liner fits inside a winter sleeping bag, letting you clean just the liner instead of the whole bag. It adds warmth for winter camping and can bealone as a summer sleeping bag,for all four seasonsINTEGRATED PILLOW SLEEVE:This zippered sleeping bag liner includes a handy pillow pocket where you can stuff your jacket for a cozy pillow while camping....