Had issues with cats climbing on top of turtle tank and made a platform. But needed to find a way to mount the lamp for the turtle. I put this together in a few minutes, but works great.

Key dimension is the 0.9" diameter receptacal hole. It is offset from the top to ensure the lamp does not get rotated.

Best if printed on the back side with the large hole facing up. The mounting holes can always be re-drilled to open up any printer irregularities.