Locknlube Grease Gun Coupler Locks Onto Zerk Fittings. Grease Goes In, Not On LOCKS ON, STAYS ON, WON'T LEAK?LIKE HAVING AN EXTRA HAND! No need to hold the coupler in place while trying to grease your machinery. The LockNLube Grease Coupler locks on tight and lets you use both hands on your grease gun. THE ONLY REBUILDABLE LOCKING COUPLER: We include a spare rebuild kit! It's like getting two grease gun tips for the price of one. 1/8" NPT COMPATIBLE WITH ALL GREASE GUNS - BATTERY, PNEUMATIC, MANUAL: Whether you are using Grandpa?s old Alemite lever grease gun, or the latest battery or pneumatic grease guns, the LockNLube Grease Coupler can be added to upgrade your grease gun. WORKS ON ALL ZERK FITTINGS, SAE METRIC with a full lineup of adapters to reach any grease fighting on any machine! RATED UP TO 10,000 PSI EASY TO USE: Press the thumb lever to open the LockNLube?s patented jaws and attach to the Zerk. Release the thumb lever and the LockNLube locks on tight! Press the thumb lever again to easily release from the Zerk, even under pressure!