3 season warmth, unbelievable breathability Sleeping bags are a big investment, but a comfortable night's sleep can really make or break a trip. For an impressive mix of comfort, low weight, and breathability in a 3 season bag, look no further than the Western Mountaineering Apache MF. The WM Apache features a trim cut: 59 shoulder girth and 38 foot girth allow the Apache to loft 6 with only 19 oz. of 850 fill premium down. Not only does the cut allow the bag to warm very quickly, but it keeps weight down to a shockingly light 2 lbs 1 oz. A full down collar cuddles the neck and keeps heat from escaping. On warmer nights, continuous baffles allow the down insulation to be pushed towards the bottom of the bag which makes the bag feel cooler. Surrounding the Western Mountaineering Apache MF is the new Microlite XP microfiber. This fabric reduces the total weight of each bag in this series by 15 to 20 percent. Despite the drop in weight, Microlight XP microfiber still contains over 400 threads per square inch to offer impressive weather resistance and breathability. Its hard to imagine a more impressive combination of performance characteristics in a shell fabric. Features and Benefits a Breathable, durable, and water resistant Microlite XP microfiber finish. a 5 14 SpacingContinuous baffles keeps insulation where it belongs. a 5938 ShoulderFoot Girth. a Full Down Collar ensures that there are no cold spots. a 6 Loft,15Adeg F rating a 19 oz. Down Fill. a Just 2 lbs. 1 oz. total weight.