This is a Heavy Duty Tri-Metal Main Bearing Set for a Jaguar V12. These bearings are made from the same material as the Vandervell VP2 bearings, Cu 74.5%,Pb 21%,Sn 4.5% with an overlay of Pb 85%,Sn 12%,Cu 3% on Ni barrier. please use pull down menu to choose bearing size.