I imagine he is talking about the motor in a Trane TWE variable speed air handler (or similar competing product)
It is a proprietary design with a motor controller board in the bell cap. When mine went bad I just had the guy put in a regular 1 speed motor. This is basically "air only" so I am not sure what multiple speeds really buys me.
The motor and controller board (both seemed bad) went for about $1000. He did the conversion, motor and service call for $275
