Due to the invisibility of CO2 lasers to the naked eye, calibrating the reflectors of the domestic K40 CO2 laser cutting machine is a challenging task. I designed and manufactured this nozzle, which can be directly mounted at the front end of the laser tube. A small, voltage-stabilized laser diode can be installed inside the nozzle. I used a battery pack to power it, with a voltage stabilized at 4.5V, which is sufficient to emit a bright and clearly visible red laser. With the help of this mounting bracket, the laser beam can be