General description High performance, low noise semi-metallic compound mounted on a steel backing plate. This product features a new formula with more copper granules for better heat dissipation and ultimate braking power, offering 2 times longer life than normal disc brake pads. Technical specifications Diameter: 21.5 mm Material: Resin Color: Black Package Contents: 8 Pairs of Bicycle Disc Brake Pads Measurement allowed error: +/- 1-3 cm