Mechanical Disc Brake MTB Bike Cycling Bicycle Front Rear Caliper 160mm Rotors Used for brake systems of ordinary bikes, mountain bikes and road bikes. Material: Aluminium alloy. Rotor material: Stainless steel . Rotor diameter: 160 mm. Position: Front & Rear . F-160mm/R-140mm. F-180mm/R-160mm. ROTOR MOUNTING BOLTS are included (2 big, and 6 small). Note: -F160/180 Front Rotor: If installed at front wheel, it fits 160mm/180mm brake disc. -R140/160 Rear Rotor: If installed at rear wheel, it fits 140/160mm brake disc. -Please check the descriptions carefully and confirm the specification of your original brake disc before purchasing.