Manufacturer Part Number: 275090. 5.5 OPTIMUM CLUTCH 2 DISC 26 SP. Without Button Flywheel - 2 Disc 1-5/32 x 26 - 5.5" Optimum-V Clutch Unit. Optimum-V 5.5" Clutch Units. Racer rebuildable internals & one-piece aluminum cover.
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