Could be mounted on a pillar, also. Don't need it anymore - plans changed. Integral switch. Mine.
Pictures and more here:
Your auction does not have any measurements.
How wide is it? How tall/deep is it?
Base is 3 1/4 inches diameter. Center-to-center of the attaching "lugs are 3 5/8" . Height (Depth if the unit is mounted on the ceiling) is a smidgen over 1 1/2 inches.
Does that help?
Thank you very much for the measurements. We are looking for something larger with the same amount of class as yours. Going to be a dome light in a center door sedan.
I sent you a PM.
Let me know please, if it does not arrive. Thanks - Dave