Outdoor Products Kilometer Hydration Pack with 2-Liter Reservoir Hands-free hydration in a streamlined, low-profile package; great for trail running, ultralight hiking, city sightseeing, and more Foam-insulated to keep water cool on a warm day, prevent freeze-ups when its cold includes 2-liter hydration reservoir and quick-connect hose; exposed reservoir cap allows easy fill-ups Breathable mesh shoulder straps with adjustable sternum strap for a comfortable fit; exterior accessory pocket Measures 16.5 x 10.4 x 1.9 inches; weighs 1.1 pound; backed by the Outdoor Products Plain + Simple Lifetime Guarantee