This is the last version of the UR aluminium Compak clutch system called V2. The Compak flywheel has been modified to fit some new R/C cars you can find on the market and avoid contact with the brake system. 

This is the V2 Ultimate Racing aluminum Compak clutch system with a conical 34mm flywheel and 3 aluminium shoes installed. The Compak clutch system is unique in that it allows you to prepare an entire clutch mounting body assembly external to your engine, and then quickly and easily remove the old one and install a new one. You just need to fit it onto the crankshaft and thread the clutch nut. It is perfect for all R/C enthusiasts, beginners and top pro drivers, and you can choose from many different clutch springs for tuning the clutch engagement to adapt the different driving styles to the different track conditions. The bigger the spring, the stiffer it is and the later in RPM range the clutch will engage. The smaller the spring, the softer it is and the earlier in RPM range the clutch will engage. 

Available in 6 different spring hardness:

B8.5: 0.85mm springs for very slippery tracks.
B9: 0.9mm for slippery track.
B9.5: 0.95mm for grippy tracks.
B10: 1.0mm. for very grippy tracks.
B11: 1.1mm for very high traction or muddy conditions.
B12: 1.2mm for Rally Game class.

This Compak clutch system is supplied with a 34mm gold anodized aluminum flywheel with tempered steel pins, 3 carbon graphite shoes, 3 springs and the clutch nut.