GZ43544 - 17mm Quick-Lock Coupler The Groz Quick-Lock is designed for quick & convenient disengagment of coupler from grease/zerk fittings under pressure. Design permits usage of all profiles of grease fittings - SAE & Metric. • Max. Pressure - 8000PSI / 550BAR. • Thread - 1/8IN BSPT. • 6-point contact design. • For use with hand & air operated Grease Guns.