The heavy-duty, grease coupler is designed for use with all hand-operated and air-powered equipment. The heavy-duty construction withstands higher pressures up to 7, 500 PSI maximum operating pressure, fits all 1/8 inches NPT threads, has built-in spring-loaded ball check valve which prevents leak, pressure loss and lubricant backup, has four hardened steel jaws for a superior seal and longer life. The coupler design permits a wide 35-degree leak-proof sealing angle, the knurled body with hex base makes for easy installation and removal, and zinc plated, corrosion-resistant finish. Lumax is a manufacturer of lubrication and fluid management products. Our products, including grease guns, manual and electric pumps, funnels, drains, grease fittings, filter wrenches, and accessories, are built to the highest standards and incorporate many proprietary features. Lumax's mission is to provide professionals and consumers with innovative and high-quality products to get the job done right. Product development at Lumax goes beyond the physical product, to a deeper understanding of the end-users' needs. Engineered with the "user-in-mind, " Lumax products are built to the highest standards and incorporate many unique features that make work easier, faster and cost-effective. We have a passion for the design process. We listen to our customers and their ever-expanding requirements. Our unique products lead the field in design, quality, and performance.