Air Assist nozzle to fit chinese 15w diode laser etcher cutter

This fits over the end of the typical Chinese diode lasers which are in the ~48mm square housings (eg. the 10 or 15w lasers). This is for a laser with a fixed focal length of around ~18mm. The laser's cutting was improved using air, less burning on the edges. I have used ~20psi which seems to work well. For hose i used some surgical tubing. In the images of the cut leather, it would have worked better if i taped down the edges because it curled up when heated and changed the focal length, but