This Magneto Cylinder / Stator Housing is the most common design used for GY6 50cc ATVs, dirt bikes scooters etc. CFW50 Inner Diameter (ID): 89.9mm Outer Diameter (OD): 109.3mm Overall Height: 37.2mm Center Hole Mount (Tapered): 10/14mm Mounting Holes (center - center) (Side by Side): 72mm Threaded Holes: 5mm