Left.w/4S. Right.w/4S. A Shield used to contain the Brake dust produced by the Brake pads of a vehicle's disc Brake calipers. This typically is mounted to the vehicle's wheel hub. Additionally, it functions as a splash guard to protect a vehicle's disc Brake rotors from water, dirt and debris. Parking Brake Support Plate. PROTECT. Splash Guard. Backing. DUST. Parking Support.