These sprockets are custom designed by SuperDroid Robots to fit the 12mm D shaft on our IG52 motors. They are made from high quality steel and have a black-oxide coating. No need to drill into the motor shaft and use rollpins with these sprockets. They have two set screw holes opposite the flat section of the D hole. Each sprocket comes with two 1/4-20 set screws.

Note: These are supposed to be a snug fit on the motor shaft. They may require a little bit of filing to get them to fit.