This is a strobe bulb. This bulb gets mounted inside the blinker housing, headlamp housing , or taillight housing.
This is a photo of a strobe bulb installed inside the blinker housing of a Ford F250. You can see the white connector ready to plug into the cable coming from the power supply pictured in the bottom photo.
With the seat removed, the power supply for the strobe system is visible. This unit sends commands to the strobe bulbs to flash in one of several flash patterns from which you can choose.
Heres a shot of a truck with the rear seat removed to show THREE power supplies set up to fire TWELVE strobe bulbs... some in the front, some in the back, and some underneath the truck.... what a show!
