CamelBak Zoid 72-Ounce Hydration Pack Low profile slim design doesn't interfere with lift and slim enough to fit under a jacket Refill easily throughout the day with External Fill reservoir Secure pocket with organizer holds keys, cash and a trail map; Omega/HydroTanium reservoir/ with Therminator harness and Lifetime Warranty. Holds 72 ounces; measures 122 cubic inches