This is a replacement clip for the Blichmann BeerGun. The clip sits at the tip of the BeerGun and holds the rubber valve seat in place, essentially stopping and controlling the flow of beer as the trigger is pulled. While the clip comes with the BeerGun, it never hurts to have a spare! Small parts can be easily lost with disassembly. Hopefully this doesn't happen to you, but if it does, we've got you covered.