Lay Western Mountaineering's Alder MF 25 Degree Down Sleeping Bag down in the meadow, and stargaze until you're ready for bed. Perfect from spring until autumn, the Alder's 850 down insulation has the loftiest fill rating available, resulting in the highest warmth to weight ratio on the market. Unlike most water resistant shells, Western Mountaineering's Microlite XP fabric offers weather protection that lasts. The MicroLite XP shell helps the down retain its lofty warmth when the meadow gets moist. Continuous baffles let you shift the down towards the top or bottom for more or less warmth. A semi rectangular shape offers more space and comfort for camping. There's a full length zipper on either the right or left side, and you can zip it around the foot to convert the bag into a blanket for versatility. The zipper also zips into other compatible sleeping bags so you can cuddle with other campers. Western Mountaineering included a waterproof stuff sack and a storage sack with a large volume that helps the bag retain its loft over time.