Buddy Bottle Seals. White Delrin 4.75mm thickness. Allows direct filling of Buddy Bottles from the standard 1/4BSP outlet found on MDE charging heads and cylinder valves. Removes the need for a hose. Suits Theoben Rapids, BSA SuperTen. And some others. Also used as a seal in the primary assembly of MDE charging heads. 2 pack. For Beaver Brand Charging Heads use our part 04B2-AC01 IMG_20150710_143014 IMG_20150710_143038.