Opens clogged grease fittings and loosens hardened grease joints. Excellent for maintaining and protecting bearings, control arms, joints, king pins, etc. Tool has an all steel construction and is designed to be tapped with a hammer to force a light viscosity oil through the tool into the coupler finally into the grease joint, breaking up and removing dirt and debris. Comes complete with grease coupler for connection onto the grease fitting and 2 spare seals for replacing the piston seals as they wear.