40 tooth timing belt pulley
The outer diameter on the teeth is around 1.47", and there are 40 teeth. Diameter of the flange is around 1.65". The teeth are 0.25" tall. The hole is threaded, and we have no clue what the thread is. Sorry. Hole size is around 0.19". Some may call this a gear or sprocket. WE CALL IT AWESOME.