410 B 11 tooth Sprocket 15 mm ID with 4 mm key way two set screws

410 B 11 tooth Sprocket 15 mm ID with 4 mm keyway, two set screws with black oxide coating.  

Sprocket is 7/8" in width.

# 410 - #43 use 1/2" pitch x 1/8" wide bicycle chain.