Coupler Pin Kit. New unique design allows the top pin to be changed without using any tools. Kit includes: two machined anodized aluminum collars, high tension spring, 2 grade 5 pins and 2 grade 8 pins. Kit works with our 3 inch driveshaft coupler we have been manufacturing since 2008. Or works with any coupler that measure 1 inch OD and 3 inches long.