LED Gyros: Each head contains a driver which is fed anything from 7-24v from the rods. Each head has a switch that allows a dim setting (150mA) or a high setting (650mA) to be selected. By using 3 rods and therefore 2 circuits, the dim ones can be on circuit 1 and the bright ones on circuit 2; switching the circuits separately gives a night time mode and a daytime mode.