The UltraFlask™ 500 soft flask is an ideal compliment to the Endurance Pack, HydraQuiver Vest Packs, Gear Vest, Adventure Pack and PFV series of Orange Mud products. You can quickly stash the flask in your front chest pocket for access on the fly plus it comes with an optional use 4" hose. Quickly take it off if you just want the bite valve, or if you want the hose leave it as is!