These pads can be used as Heavy Duty for Triumph Spitfire 1967 to 1980. They have 15% more braking area and fit in the stock caliper. They also fit Morgan 4/4 1600, TC, 1600 (OHV) 1968-85, Jensen Healey and GT 1972-76, Lotus Esprit S1, S2, S3 1975-87, Ford Capris Mk I and II 1968-77, Triumph Dolomite 1973-80, Toledo 1970-76, Hillman Avenger 1976-78, Sunbeam Lotus 1976-79. These are the best pads that you can buy for your car. Each pad has an anti-squeal shim glued to the back of the pad for silent braking. As for composition each pad is made from Ceramic material for an almost dustless braking and helps with high temperature brake fade. No more black rims to clean on your car and youíll have confidence in braking. LUCAS / TRW