Overview Reviews Product Description Flywheel Key for ARC Billet Cranks. 4mm x 16mm Will Not fit OEM cast Honda/Clone or Predator cranks. Product Videos Custom Field Product Reviews Write a Review Write a Review × 903704 Flywheel Key 4mm x 16mm Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *