Supercharger Pulley | 16% Overdrive | Factory Eaton Supercharger - MINI Cooper High precision CNC machined. Active cooling slots pull in cool air to reduce belt temperature. High bolt torque adds maximum clamping force to the superharger shaft to eliminate pulley-to-shaft slippage. Fits the Eaton supercharger in the stock location for perfect belt alignment. Pulley body is matte gold anodized billet 6061-T6 aerospace grade aluminum alloy.