Allen Summit Ultra-Lite Hydration Pack: * Hydration ready, holds up to a 2.5L bladder (bladder not included) * 1075 cu in capacity * 17"L x 10"W x 4"H main compartment * Cool mesh vented back and shoulder straps * Vented hip pads with 2" web belt that adjusts to 54" * Waterproof material * Quiet zipper pulls * Bungee cord system for carrying extra clothing * Additional "jam pocket" for carrying spotting scope or shovel * Extremely lightweight