Description It is important to store your sleeping bag outside of it's stuff sack. Long term storage in the stuff sack will cause the insulating material (synthetic or down) to clump together, reducing its insulating properties. The Cotton sleeping bag storage sack is designed to keep your sleeping bag well ventilated and uncompressed. Features Fits all First Ascent sleeping bags Cotton material keeps your sleeping bag ventilated First Ascent Cotton Sleeping Bag Stuff Sack