Emergency vehicles in some places use what is called Opticom, a device made by the friendly people at 3M*. It consists of a strobe light flashing at a certain frequency mounted on the vehicle, and a sensor on the traffic light. The sensor sees the strobe light, and changes the light to green for that direction.
More about it here: http://www.3m.com/market/trans/its/prod_priority.html
Perhaps they’re trying to sell a counterfeit transmitter unit? Of course, it would only work if your locale used Opticom.
*This is in no way to be considered an endorsement or advertisement for the 3M corporation
Jeremy…
Nobody ever calls me after they’ve done something smart.