12T 20mm #428 centrifugal clutch

High Quality Go Kart Tractor Mini Bike Cyntrifical Clutch 5/8″ Bore
Accepts 35# Chain (3/8″ chain pitch) 11 Tooth Sprocket Racing Centrifugal Clutch
Set Screws Not Included, designed for Single Wheel Drive Karts with Tires no larger than 15″ Tall
Mounts onto crankshaft using bolt and washer on the end of the crankshaft does not have set screws.
Bi-directional operation, Easy to install