A contoured back panel and an integrated Mil Spec Antidote Lumbar Reservoir that transfers weight from the back to the hips makes this CamelBak's most comfortable pack for one or two day excursions. | SpecificationsTotal Capacity: 33L (2014 cu in) + 3L Reservoir | Dimensions: 20.3 in x 14.6 in x 12.1 in (52 cm x 37 cm x 31 cm) | Cargo Volume: 2868 cu in (47L) | Total Volume: 3051 cu in (50L) | Weight w/ Empty Reservoir: 5.8 lbs (2.65 kg) | Materials500D Ripstop Cordura fabric front panel, gussets and shoulder harness front side | 420D high density nylon on shoulder harness back side | Air Mesh back panel | 8 mm EVA foam shoulder harness | 3 mm PE foam for hydration compartment divider | 210D Nylon lining | Nylon webbing 7 mm closed cell PE foam back panel

Reservoir

100 oz (3L) Mil Spec Antidote Lumbar reservoir | 42 in (107 cm) PureFlow tube | Insulated tube cover | Black Big Bite Valve | Black QL HydroLock | Bite valve cover | FeaturesMil Spec Antidote 3L low-profile, baffled Lumbar Reservoir integrates into hydration compartment and for a more comfortable and ergonomic load carry carriage | Sleek, low-profile composite MOLLE panel provides secure attachment for pouches and gear | Internal MOLLE panel allows custom configuration of essential gear/pouches | Composite MOLLE on harness for front-facing pouch attach | Contoured back panel for a more comfortable and ergonomic carry | Full clamshell opening for easy access to main compartment | Lower access zipper allows you to quickly stash or grab an item from the main compartment | Zippered back panel access for loading reservoir into separate insulated lumbar reservoir compartment | Front pocket organizer | Internal mesh pocket | Upper and lower compression straps | Two internal main compartment adjustable lash straps to secure large or bulky items | Multiple drink tube exit ports for routing tube over the shoulder or under the arm | ASIPS radio attachment points hold communications securely with dual antenna ports | Fully adjustable waist-belt stows easily when not in use | Adjustable sternum strap | Lightweight, durable 500D Ripstop Cordura