Wilwood 120-13293 Wilwood 1.75/1.38/1.38 AERO6 Caliper 1.25 RotorWilwood 120 13293 Wilwood 1. 75 1. 38 1. 38 AERO6 Caliper 1. 25 Rotor The new Aero6 forged six piston caliper delivers heavy duty stopping power for the road or track. The caliper incorporates race technology into a body design with widespread adaptability. Radial mounting, multiple options for piston volume, and a rotor diameter ranging from 12. 88" to 15. 00" give this caliper the versatility necessary to suit all types of heavy weight braking