Used this motor to replace the burned up one on my IR 5 HP compressor. I had to use smaller bolts than what came off. Other than the bolts, it was a perfect replacement. They don't advertise, but in the instructions are the wiring changes to make motor turn opposite direction. Motor seems quieter than original. Interesting topic - I live in New Hampshire and once a year, we oil undercoat our vehicles. This is a day long process and the air compressor sees 95% duty cycle almost all day long. Last year the motor went out and tripped it's thermal fuse with \"warm\" smell. This year, with this new motor, no smell, no thermal overload.