Ralco RZ Xtreme Stage 4 clutches are designed for the individual whose goal is to have an ultimate strip/track clutch system. Ralco RZ Xtreme Stage 4 clutches only consist of the very best materials available. The pressure plate is made from the forged ductile iron (3X stronger than the conventional cast iron pressure plate) to ensure consistant clamping force and the extra long life. Virtually indestructable 6-puck solid race discs have a high capacity center hub for a precise and direct clutch engagement. The 6-puck copper ceramic (also known as 'MIBA') disc features high-coefficient friction pads that are resistant to slippage and burst. The Ralco RZ Xtreme pressure plate features special single diaphragm design to increase clamp load. It features induction hardened diaphragm, CNC machined castings, stronger drive straps and rivets. Ralco RZ Xtreme pressure plate provides smooth and precise feel with easy modulation. All Ralco RZ pressure plate is load tested on a special testing tool for quality assurance.