Camshaft internal metal Labrinth Seal (Metal Bushing) for advance rod. 2 used per camshaft on 1970-79 models (Points ignitions) and also required if using Boyer ignitions. Fits inside of camshaft and flush with ends (one each side). Note: These are usually missing from 1980-84's. Interchangeable with part #05-0034. OEM Ref.# 256-11155-00.