Train Tech Smart Light - Emergency Vehicle The Smart Light developed by Train Tech is a new system which can easily be fitted into buildings, locomotives, vehicles and other areas of your railway. The light is just 1cm square and simply connects to a 9 - 16 volt power supply and only requires 2 wires and no additional setting up. It can also be fitted to a battery for portable usage. Realistic multi-flashing blue light which can be fitted under a roof light on police, ambulance and fire emergency vehicles.