I'm a roboticist and engineer, the motor is high quality construction and the motor control unit has A LOT of functionalities, which is great, motor performed as expected, however the output shaft is not a widely used style, and required metric sprockets that were hard to find, even on McMaster Carr, so I ended up getting rid of the original sprocket, and custom milling my own on my CNC machine. The motor works great, the main reasons for 4 and not 5 Stars are the poor output shaft being a non-standard design and the fact it came with literally no manual or instructional booklet, although the wires for the motor controller had Mandarin and English writing saying things like "Break Light" or "Door Lock", I wish it would have come with a electronics manual at the very least so I didn't have to do an hour of diagnosing to determine what each of the many outputs on the motor controller did and whether or not they were essential to get it to run. Besides that, great motor.