Opens clogged grease fittings and loosens hardened grease joints Excellent for maintaining and protecting bearing, control arms, joints, king pins, etc All steel construction tool is designed to be tapped with a hammer to force a light viscosity oil through the tool into the coupler and finally into the grease joint, breaking up and removing dirt and debris Built-in hand guard for added safety Flexible hose attachment reaches fittings in difficult areas Comes complete with grease coupler for connection onto the grease fitting and (2) spare seals .