The Outdoor Research DryComp Summit Sack features waterproof fabric and a roll-top closure that protects your gear on the approach. This ultralight and waterproof day pack has all the features needed for a fast and light summit push. An Airpurge strip allows for maximum compression, as the air-permeable fabric allows the complete evacuation of internal pressure. Radio frequency welded seams and reinforced fabric on the bottom and pocket area provides maximum strength and waterproofness. A mesh pocket accommodates a hydration bladder, and stretch cording and gear loops secure crampons and ice tools. On the final push the compression straps convert to shoulder straps and a waist belt, and the DryComp becomes your summit sack. The ergonomic design fits flat against your back. Dual daisy chains with ice axe loops on the OR DryComp Summit Sack take care of your climbing and mountaineering equipment.