locknlube grease gun coupler locks onto zerk fittings. grease goes in, not on the machine. world's best-selling original locking grease coupler. rated 10,000 psi. long-lasting rebuildable tool. locknlube <ul><li>won't leak once locked on</li><li>hands-free, does not release under pressure</li><li>rated up to 10,000 psi</li><li>1/8 npt thread. works with all grease guns</li><li>grease goes in, not on, the machine</li><li>works on all zerk fittings, sae and metric</li><li>comes with free replacement seal and jaws. fully rebuildable</li><li>easily releases from clogged grease fittings, even under pressure</li><li>patented locking technology. us patent #8955544</li></ul>