I don't have the DX-1 probe for the MXT but do have the S-1 for the Sov GT. What they are is really a one inch coil that runs off the detectors circuits. You coil cable plugs into the DX-1 control box that has a two position switch, one side Coil and the other Probe. When switched to coil your detector runs like normal. At the Probe position you can use the probe as a coin probe that will have a range of about 8" off the tip. You can't forget it. The sound comes thru your speaker or headphones like normal.