Product Details: Prepare your semi for the journey ahead with smooth front and rear brake performance, with the OTR 1.46" U-Type Air Disc Brake Rotor with Expertise Built In™. Thanks to its partnership with the brake pads and caliper, this replacement rotor is able to create a compression mechanism that slows a vehicle once the brake pedal is activated. Crafted with precision standards to remove defects and provide long-term durability.