C-420 Chain Sprocket 10 Tooth And 20 Tooth 5/8 Inch Shaft Diameter Sprocket With

Compatible Chain Types: For 40, 41, and 420 chain types. Item Type: Mini Bike Chain Sprocket Kit. Large Sprocket Teeth: 20T. Small Sprocket Teeth: 10T. 2 x Sprocket.

eBay