Rear Sprocket #31 fits #420 Chain - (37T) (30x40)

This Chinese ATV rear drive sprocket uses a #420 Chain and the center hole measures approximately 30mm.  Measuring directly across center from mounting bolt to mounting bolt is 40mm.  All 3 mounting holes are NON-threaded and use M8 bolts.

These original equipment replacement rear sprockets will interchange with many other brands and models of Chinese ATVs, Dirt Bikes, Scooters and Go Karts.