reverse mirror alignment tool

Summary
I got the idea of the following thing: https://www.thingiverse.com/thing:4696157
But designed it from scratch in Fusion 360 (easy design), because the mentioned boresight is expensive in the Netherlands, and I already had a red dot laser.

CHANGES:
Adapted outer diameter to 24 mm laser gauge, this matches the cloud ray type C laser heads (and proberly others).
Added holes for 4x M3 screws that help align and fix laser in position
Made the hole for the red dot laser, 10 mm. So it will fit the more "normal" laser in the Netherlands.

ORIGINAL DESCRIPTION (with editions that apply):
This is a "reverse alignment laser" that you can use to align a CO2 laser mirrors starting at the end furthest from the tube.

CO2 lasers are invisible IR so you usually use a "scorch test" where you stick some tape in front of the mirror (not on it) and turn the laser on till a black burn appears. You adjust the mirrors one at a time starting at the laser tube till the laser is burning in the same spot regardless of the position of the moving mirrors.

This tool works the same way except you start at the mirror furthest from the tube. Because the beam is visible its safer and you don't have to keep opening the lid to adjust or see something.