Gold™ Solid Rear Brake Rotor (18A2418) by ACDelco®. Quantity: 1 Per Pack. ACDelco Gold™ Disc Brake Rotors are metal discs mounted to the wheel hub where the caliper can press the brake pads against the disc surfaces to slow the vehicle, and are GM-recommended replacements for your vehicle’s original components. These disc brake rotors have been manufactured to fit your GM vehicle, providing the same performance, durability, and service life you expect from General Motors.