RAM Clutches 550 Required Shim Set for Sintered Iron Single Disc is a member of the RAM Truck Pulling Clutches – Single Disc Series. This expertly engineered Required Shim Set designed for installation of Ram Clutches Sintered Iron Single Discs. Expertly engineered for Light-Duty Pulling where limited 'slip' in the clutch is required. A Long Style pressure plate with counterweighted levers is used in conjunction with a Six-Paddle Rametallic disc. This setup will provide moderate increases in holding power on the low end and the Centrifugally Weighted Levers will add more clamping pressure as the engine RPM (Revolutions Per-Minute) climbs. The Light-Duty Pulling clutch is best utilized for applications where the vehicle is still street driven or is occasionally used in competition. RAM Clutches are the Champions Choice.