Mountain equipment womens helium 250 sleeping bag left zip weighing less than most bottles of water and packing down equally small this is the perfect bag for the dedicated warm weather backpacker features helium tm 20 outer shell is very light and highly breathable 243g of 90 10 pure duck down with a minimum fill power of 700 alpine fit with zoned exl system maximises thermal efficiency slanted box wall baffles and stitch through baffles mid level side seams 5 baffle anatomically