valv-oring - Each kit contains 4 valve cap O-rings, made of special material to withstand the heat - these are not generic run of the mill o-rings! These fit most/all NON-DESMO bevel drive engines which use O-rings and not the other modern DESMO valve caps. PLEASE NOTE - some early desmo engines have both these ORING TYPE and the earlier CAP TYPE seals and some will have only the cap type seals..... Best to check it out before ordering.