Spark plug sealing ring, fitted between the valve cover and cylinder head.

To fit:
944 S 2.5 1987-1988 - 4 required per engine
944 S2 3.0 1989-1991 - 4 required per engine
968 3.0 1992-1995 - 4 required per engine
928 4.7 1983-1986 - 8 required per engine
928 5.0 1987-1991 - 8 required per engine
928 5.4 1992-1995 - 8 required per engine