STM clutch conversion from the original  Wet clutch to the STM dry clutch. 
 
 Difference to the EVO SBK: 
 Outer basket with 40 teeth and extra "cooling fins" (see picture Z40 Basket)
 
 Advantages of an STM dry clutch:
 - Less power loss over the dry clutch
 - Contributes significantly to preventing engine overspeed when downshifting
 - prevents a skipping rear wheel
 - reduces the trigger impulse of a highsider
 - controlled sliding  of the rear wheel possible
 - easier to control the  Closing phase of the clutch in curves (to avoid pitching).
 - enabled  a better feeling when releasing the clutch lever (start) thanks to the diaphragm spring. (a wobbling of the pressure plate is avoided)
 - Significant weight savings (reduction of the rotating masses) ~0.7-0.8 kg
 - Patented ball ramps to control the anti-hopping function