Joints and fittings that will not accept grease may be clogged with hardened or contaminated oil. The Grease Fitting/Joint Cleaner allows users to easily open clogged grease fittings and joints, according to the company. The tool injects light-viscosity oil into the grease joint to remove dirt, rust and other materials. After a few taps, the tool's piston moves down into the tool body. This indicates that the fitting or joint is open and ready to be greased. The tool comes with a limited-lifetime warranty.