Grease gun couplers are the linking connection that secures a hydraulic grease gun hose or rigid extension to a grease fitting’s head allowing the gun to effectively dispense grease or lubricant through the grease fitting. They are a critical component to lubrication systems and come in a wide variety of shapes and sizes to accommodate the array of grease fitting styles they connect with. Most couplers are made from 12L14 steel with heat treated hardened steel jaws and zinc chromate plated bodies with aluminum couplers available as well.