This Montbell sleeping bag cover is not only ultralight, but it is also waterproof. Full sealed seams promise you will stay dry, and this cover also features excellent breathability and reduced moisture. This sleeping bag cover is made with a 2-layer Breeze Drytec and can’t be used without a sleeping bag. Weighing only 6.3 ounces this cover is a must-have for your next adventure where weather in the rugged Sierra Nevada can change at any minute! Weight: 6.3 oz.