Upright IRS Wheel Studs 14" 4-Piston Radial Mount Caliper 14" x 1.25 Vented Slotted Drilled & E-Coated Black Rotor for IRS Rear Unit Hub-AA Upright With 4-1/2 & 4-3/4 Wheel Stud Bolt Circles. With Caliper & Parking Brake Options Clearance Notes: Brake Register is 3.06, Caliper Extends Past Hub Face .40", Caliper Outside Maximum Diameter is 14.50" ------- SPECIAL ORDER PART NOT CANCELABLE OR RETURNABLE FOR ANY REASON---------