Brake shoes, 10" x 2-1/2", 65-67 Shelby Mustang rear, Carbon Kevlar race compound. These direct replacement shoes are lined with Carbon Kevlar material that is both bonded and riveted for added strength. Carbon Kevlar material provides superior stopping capability combined with a very drum friendly nature. We believe the R4 compound to be one of the best all-around compounds for “Full Race” competition use. Optimum operating range is 450F to 1200F. This compound “beds-in” quickly so you can concentrate on driving at speed almost immediately.