Pin Type couplers. We do not sell, install, use, or recommend the older ball type couplers for any plow hydraulic system. We only use these Pin Type couplers. In our experience they have been compatible with the E-57 Pin Type Couplers on the PA Block (which these will NOT replace). These are rated for 4,000 psi working pressure. Inferior ball type are usually rated at 3,000 psi. Remember, your Crossover Relief Valve doesn't open until the system builds 3,800 psi! Might be Zinc Chromate (gold) or Zinc plated (silver) we cannot control the color. These are not cheap junk couplers! Fits E-47 and E-60 units, both hose ends and if the old style PA Block, the elbows on the unit as well. These are NPT threads so they will not fit the newer E-57 style PA Blocks that have SAE threads. This can be determined by looking at the PA Block on your E-47/57/60 unit. IF it has one fitting coming out of the side of the PA Block, it is SAE and these will not fit your PA Block. Scroll through ALL images to see the difference. Does NOT fit E-58H, E-68, E-88.