Polyester/Cotton Blend, Which Combines The Comfort Of Cotton With The Strength And Light Weight Of Polyester. Add Additional Warmth To Your Existing Sleeping Bag. Use Alone, Or Use It To Keep Your Bag Clean. Stuff Sack Included.table.productattributes, .productattributes td { border-bottom: 1px solid #ddd; border-collapse: collapse; padding: 2px; text-align: left; }