15lbs Rad cap, This is a Radiator Cap 15lbs for MGB 1977 to 1980, MG Midget 1970 to 1975, and Triumph TR7 and TR8.

Fitted from A plus on to increase engine running temperature. If your radiator has a sender unit in the bottom you may have an expansion tank and therefore the radiator will need a better sealing pressure cap which allows a small vacuumGRC207.