Features and Benefits: 6-Jaw Coupler with high strength steel jaws provide improved clamping force on the zerk; Releases easily under high pressure; Spring latch for positive engagement; Ergonomic Thumb Lever provides effortless one-handed coupling and uncoupling, even under pressure ‐ no more struggling when removing the coupler; Compact design is ideal for use in tight spaces, 2.9 in. long by 1.2 in. tall; Compatible with all sizes and forms of mounts, fits all SAE and metric zerk fittings; For use with most manual, battery and air operated grease guns and pumps;