The Scorpion offers 2 liters of winter hydration, external fill for quick refueling, and just enough cargo capacity for tools, tunes and some food.Therminator harness and insulated tube help keep water from freezing.Includes SternumStrap for more comfort and stability.Refill easily throughout the day with external filport access.Zippered CD/MP3 pocket with headphone port.Includes Antidote reservoir to make filling fast and easy.Low profile design can be worn under a jacket.Made of 600D Poly P-U/210 Nailhead Dobby/210 Diamond Ripstop Nylon.Size: 16.5 in. x 9 in. x 4 in.Wt: .9 lbs.Capacity: 70 oz. (reservoir), 200 cu. in. (cargo).