Fend off frozen drink tubes and help keep liquids cool in hot weather with the Platypus Drink Tube Insulator. The new design offers a completely covered bite valve (to keep it clean and protect it from freezing quickly), a reverse coil polyurethane-coated zipper (to prevent ice/snow build up), a large zipper pull (to easily open with one handeven with gloves on), and a hook and loop closure shoulder strap attachment (to secure to a pack). Works with all Platypusdrink tubes and bite valves.