Upright IRS Center-Lock Hub 15" 4-Piston Radial Mount Caliper 15" x 1.25 Vented Slotted Drilled & E-Coated Black Rotor for IRS Rear Center-Lock Unit Hub-AA Upright. With Caliper & Parking Brake. Options. Clearance Notes: Brake Register is 3.06, Caliper Extends Past Hub Face .40", Caliper Outside Maximum Diameter is 15.50" ------- SPECIAL ORDER PART NOT CANCELABLE OR RETURNABLE FOR ANY REASON---------