[Specifications] Type:Bike Front Rear Brake Caliper Material:aluminum alloy Features:MTB Disc Brake Pads Adjusting Tool, Disc Brake Rotor Alignment Tool Size about 8.5 * 5 * 4cm / 3.3 * 2.0 * 1.6in Special note: Please look at the installation hole distance, the installation hole distance is 51mm F160/R140: for the front 160mm Rotor Disc/rear 140mm Rotor Disc F180/R160: for the front 180mm Rotor Disc/rear 160mm Rotor Disc