These European made waterlocks are manufactured from high density polyethylene to a high standard and are suitable for wet exhaust systems having hose diameters ranging from 55mm to 90mm. Simply trim off the stepped tails to the required size to suit the hose diameter of your choice. These waterlocks provide adequate noise suppression for most small to medium propulsion engines and generators. Depending on the relative height of the waterline, care must be taken to prevent water back-siphoning into the engine by installing a gooseneck and syphon break.