With the LockNLube(r) Grease Coupler, no hands are needed to align or hold the coupler in place while greasing. The product features a sliding sleeve activated by a thumb lever that locks the four spring-steel jaws onto the zerk fitting, reportedly creating a leak-proof seal. Depressing the thumb lever releases the coupler, even if the fitting becomes pressurized. The LockNLube® fits electric, pneumatic, and manual grease guns with 1/8" NPT hose connections.