410 B 20 Tooth 5/8" ID Sprocket, 2 set screws with 3/16" keyway Zinc Plated.
The hub is 1" wide.
These sprockets are made to be used with 410 - 410H chain but can also be used with the wider 415, 415H (1/2" pitch x 3/16" wide) and with the wider #41 chain that is (1/2" pitch x 1/4" wide).
Weight: 1.80 lbs