End greasing frustration with the original locking grease coupler. Locks on, stays on, won't leak. Rated up to 10,000 psi. Easily disconnects, even under pressure. No more broken Zerks. The 1/8 In. NPT compatible with all grease guns - battery, pneumatic, manual. Grease goes in, not on, the machine. Works on all Zerk fittings, SAE and metric. Includes a rebuild kit! The LockNLube is theworld's only rebuildable grease coupler, lowest lifetime cost. Patented Locking Technology (US Patent #8955544).