This soldering kit can be used to make a fully functional traffic light model. The three traffic light LEDs can be mounted on the board or on the enclosed wooden kit. This creates a traffic light model that is approx. 9 cm high. Function: If the electronic traffic light is operated with a DC voltage of between 3 volts and 16 volts, we recommend a 9-volt block, it switches from green to yellow to red and back again like a real traffic light. The time between red and green can be set with a potentiometer to between 10 seconds and several minutes.