The Gregory Z55 Internal Frame Backpack is a workhorse that's light and durable and carries like a dream. Thru hikes, lightweight three-day weekends, or trips to the crag are just a few places you'll enjoy wearing this classic.JetStream LTS suspension with 3 waistbelt size adjustment options. Dual hydration ports and sleeve. Top load and side zipper access that goes the length of the pack. Removable top lid. Side, bottom and top compression. Quick access waistbelt pockets. Exterior side pockets with pass through compression. Dual axe/tool attachment points with more secure carry under front pocket fold. Water resistant zippers. Front zippered pocket. Expandable front bucket pocket. Torso Length: M-18" - 19"/ L-20"-21.5" Number of pockets: 4 Materials: 210D double diamond ripstop and/210Dx 420D Hd flat weave Size: n/a Weight: S - 3lbs 13oz/ Med - 3 lbs. 14 oz. / L-4 lbs. 3 oz. Capacity: S - 3112 cu. in./ M- 3417 cu. in./ L- 3722 cu. in.