Thanks Steve. The text provided indicates the Class A is for a commercial environment while Class B is for a residential environment. That clears it up. The vendors are able to provide UL, CSA, CE, and CCC and are of course RoHS compliant. My company is already ISO 13485 certified, so Health Canada is covered. Interestingly, our device, a specialized power toothbrush, is considered a cosmetic device in USA, but a Class II Medical Device in Canada. Still wondering about that "Switching question"