Air Assist Clamp and Cap.
Air Assist Clamp and Cap for K40 style 40W Chinese blue and white CO2 laser.The clamp and cap will hold/fit a 1/4 inch OD tube. I used a scrap of copper tube from an icemaker water line. The cap file has two caps. One at .5mm larger. Choose your best friction fit. The screw holes are 4MM on top, and 2mm on the side. you may have to drill out the side holes a bit.