A lot of those motors are custom made for different manufactures of products. If it doesn't show up on a spec sheet, then you would have to contact the manufacture directly. A lot of times they won't give out the information because it is priority only. Meaning you can only get the info from the end user, if even they will tell you who it is. A lot of times it could refer to a different placing of the screw holes, reversal of the motor leads, etc.....