Up for sale is Comet COMET 108 4-PRO CLUTCH. The vendor part number is 219603A. Read title carefully to know what you are getting. Catalog description . Go for the gold with Comet’s 108 4-Pro clutchAdded fourth load-bearing member increases roller and buttonlifeThese race clutches are for high-performance applications ONLYTo determine arm,add weight of three arms used in 108 EXP, add14%, then divide by four, this will be the new arm weight touseClutch use four clutch weights to greatly enhance turnabilityArms can be used in sets of two to better zero-in desiredweightCaptivated tower allows shouldered cover bolts to virtuallyeliminate tower spreadingEach Features a new bushing in the movable face and redesignedfixed face for increased durabilityIMPORTANT NOTE:These clutches are for racing use only. For calibration,contact a high performance specialist or Comet Industries.