Made from hardened steel, these locators use an inboard locating shoulder to center the seat and hold the spring in place. The 4678 seat's 1.285" OD works well with our 26918 beehive springs. PartNumber : cca4678-16 Description : COMP Cams Spring Seats .135 x .810 x .880 x 1.285 (set of 16) California Proposition 65 : WARNING: Cancer and Reproductive Harm P65Warnings.ca.gov Locator Inner Diameter : 0.805 Locator Outer Diameter : 1.285 Locator Thickness : 0.135 Spring Inner Diameter : 0.88 Title : ID Spring Locator Set of 16 - 1.285" OD, .805" ID, .135" Thickness Engine Components::Valve Springs, Retainers