These Pony Bottle Holder Kits are some of the best made all aluminum and stainless-steel construction with no hose clamps to break or puncture your B.C.D. Changes with just the pull of one pin. The bracket slips easily under divers BCD tank band or any 2" (5.1cm) webbing strap. Tanks change easily - no tools needed. Bottles can be swapped in seconds. Hand-off your pony bottle to your dive buddy in seconds, underwater.