This is an adjustable laser pointer holder for use on anything with a Vixen-style mounting bracket. Inside diameter of the rings are 37mm, so it would hold a rather large laser pointer, if needed, but it works well on the pen-style ones.
Pics are of the first version of this. I had to increase the rigidity in the center section because it was flexing too much when you would tighten the bolts down.
I used 999 top layers instead of 100% infill. I believe it gives it better internal strength. But it's really just personal preference.
All parts can be printed without supports. You'll just need to flip them like the pic in S3D I have above.
I used two #6x1/2" pan head screws with nuts to secure the pieces together. I left the holes small enough that you can drill out whatever size you need for the hardware you have.
The adjustment bolts that hold the laser in place are #10-24x1/2". You'll need 6 of them.
I did make a 1/2" drilled hole in the bottom of the base to make it easier to install and tighten the nuts (it doesn't really affect the rigidity of the base). You can see that in the pics above.