[Blackpowder44 (RIP)]

The measurements for the Diff. Light are tube length 3 1/4 ins. Diameter 1 5/8. as has allready been said, the light and switch are fixed on the chassis or the rear cross member so that the light shines forward onto the White painted dif, or in the case of a trailer , onto a white painted plate. The picture on here is the light fixed onto my Jeep. It is rather misleading because the pic appears to show it closer to the Dif than it is, hope this helps. The wiring for this light is on its own circuit for convoy blackout lights and not linked to the main lighting circuit. John.PS attachments are US at this time, will try later.