Might not be as good as a factory job but here is a SR-60 with bluetooth, the little purple thing is the battery that powers the serial to bluetooth adapter. It was made to charge cell phones, the adapter is really for machines like in a factory and you use the adapter to get rid of cables. You ask why this is needed? Now I can stream the locator info like depth to a hand held GPS-Computer that can track the exact position (sub meter) of the sewer while walking over it and the depth combined. Someday this will be the normal routine in larger cities. There are a lot more possibilities.