I also emailed, and they wouldn't tell me. My compressor can handle it, I checked the specs that the griots catalog said I needed. I think the orbital is a dynorbital, and I have searched for them, and griots prices dont seem to be more than 10 dollars more. If you download the instructions on the orbital from their website, it says that it is a dynorbital orbital buffer, but I have yet to find one online that looks exactly like it.