Product Details: The Lincoln Industrial Heavy Duty Hydraulic Grease Coupler is designed to provide a secure connection for all hydraulic-type grease fittings. It features a 1/8" NPT connection size and 11/16" hex size for easy installation. The coupler is constructed with hardened steel jaws that can be replaced and a built-in ball check to prevent leaks and lubricant backup. It is designed to handle a maximum working pressure of 7500 psi, making it ideal for heavy duty applications. FleetPride is your First Click in Heavy Duty®.