This is a A-A31867 Lock Nut, M12 X 1.75 Hex Deflected PN: A31867Main Description As Following : A-A31867 Lock Nut, M12 X 1.75 Hex Deflected PN: A31867 Found in Section & Models : Miscellaneous > Miscellaneous, (Miscellaneous) (UNDEFINED): SEVERAL Associated Items : New Also This is An Aftermarket Product And : Thread Size: M12 X 1.75