StopTech Drilled Sport Rotors are 1-piece direct replacement brake discs for your factory brake system and stock calipers. These 'Sport Rotors' provide substantially improved stopping power and cooling compared to standard rotors. This part number (128.33113R) refers to the Right Rear side. Key benefits include: cross-drilled holes for improved heat dissipation and gas venting, a special e-coating finish to prevent corrosion on non-friction surfaces, and a high-performance look behind your wheels. Technical specifications: Diameter: 310mm, Height: 48.2mm, Thickness: 22mm (Vented). This is a single rotor (1 unit).