The Black Diamond Standard Hydraulic Coupler is designed for use with hand-operated grease guns, delivering a secure connection with a narrow profile for fittings in limited-access areas. A milled slot allows easy tightening, while fully hardened spring steel jaws provide a firm, long-wearing grip. The 4-jaw construction with a ball check helps maintain a consistent seal during greasing. Threaded 1/8" NPT with a 3,000 psi working pressure for dependable performance.