There are long runs, and then there are epic runs. Our most versatile running vest is designed to handle both. It's got 2 liters of hydration capacity, a sweat-proof storage compartments for your keys and phone, and a stretch mesh pocket for gels or salt tabs. The external-fill feature also lets your refill your reservoir without removing it from the pack, so you can save time on the trail. Worried that the weather might turn on you? The stretch mesh compartment expands to hold an extra layer or two. Need more than 2 liters of water? Load up the chest pockets with two extra bottles. And with two sternum straps and a hook-and-loop adjustable harness, this pack stays put now matter how rough the terrain. Hydration Capacity: 70 oz / 2L. Total Capacity: 244 cu in / 2L + 2L Reservoir. Total Weight: 13 oz / .38 kg (pack only). Dimensions: 21 x 13 x 2 in. Torso Length: 14 in / 36 cm. Fabric: 70D reverse chain nylon w/ 230 taffeta. Empty Reservoir Dimensions: Air mesh. Materials: Adjustable with cargo pockets and dual slider sternum strap. Fits 30"-46" chest.