Patagonia Stealth Atom Sling Polyurethane-coated 840-denier 100% ballistic nylon is durable and protects contents with a DWR (durable water repellent) finish. Pack size is 15L Molded front drop-down panel with interior fly keeper; main zip pocket holds two large fly boxes and has interior hook-and-loop closure storage pockets; top drop-in mesh-lined security pocket; TPU-welded waterproof interior pocket Exterior YKK zippers with covered welt are highly water-repellent Pack: 9.15-oz 840-denier 100% ballistic nylon. Interior: 3.3-oz 100% polyester. Back and back of sling strap: 3mm 100% polyester air mesh. All with a polyurethane coating and a DWR (durable water repellent) finish 623 g (22 oz)