410 18 tooth Sprocket 5/8" ID with a 3/16" key way and two set screws & zinc plated.
This sprocket has a 1/2" pitch x 1/8" wide teeth.
This sprocket has a 1" wide hub.
These sprockets are made to be used with 410 & 410H chain.
It can also be used with the wider 415H (1/2" pitch x 3/16" wide teeth) and with the wider #41 chain that is (1/2" pitch x 1/4" wide teeth).
Actual shipping weight is 1.30 lbs.