I have just recieved an ellectric rotary impact drill, but the plug end has 2 round pins, not flat. My question is what would happen if I replaced the end with a regular plug. There are next to no markings to give any clues, is it ac, or dc, 220, or 120 volts. If its 220 like I suspect would it just run slower on 120 or would something get harmed. My only clue is if someone recognizes the two pins on the plug.