This is intended to go along with the 30mm mirrors cut from hard disk platters. If you want to use real mirrors, you can do that too. Just keep in mind that the optimal distance from the mirror to the mount block should be around 2mm. This design has been tested on a 100 Watt CO2 Reci Laser tube, with no major problems. The laser was well aligned beforehand. YMMV. I would recommend this for 40 Watt CO2 laser tubes, or lower, as the mirrors tend to get very hot on the larger lasers. Gluing a heat sink back there might help. I'll be some images with a FLIR to see if the mirrors deform at all during lasing. All hardware is 3mm. The three shoulder screws are meant to hold an elastic band or o-ring to act as the spring for the mirror angle adjust. Thumb screws are 12mm in length. Regular screws will do in their place. The nozzle tube v3 has a slight taper on the end to make it slip on easier. Also the neck around where the lens goes has been strengthened.