COMP Cams spring locator seats set of 16, made from hardened steel with an inboard locating shoulder to center the spring and hold it in place. The design helps position valve springs accurately; the 4684 seat has a 1.285" outer diameter specified for compatibility with compatible springs and guide applications described by the manufacturer.
COMP Cams Spring Locator 1.285in x .532in x .135in (Set of 16)