If you use your laser in a housing, you will have a lot of smoke inside the housing if you cut or engrave wood. The cooling fan inside the laser module uses this dirty air for cooling. To keep the laser module clean inside, I created this connector to mount an airhose to the module. So the module is cooled with fresh air from outside the housing.
Here is a link to the airhose I used.
Please do not request other diameters. If you need other diameters, I recommend to check out this model at thingiverse:
https://www.thingiverse.com/thing:6324762/files