Dynabrade are great die grinders too, I have 1 ARO/IR 18K RPM, 1 Dynabrade 12K RPM, 2 IR revolutions 25K RPM die grinders. The dynabrade is my weld grinding/hogging grinder because it is rated at 1hp and there is no doubt that it is powerful.
I think dynabrade and dotco are most likely about...