Laser safety using Opt Lasers accessories.
Engraving and cutting with lasers requires eye safety. By investing on proper laser manufacturer tools like Opt Lasers offers, you can work as safe as possible with lasering. They offer safety glasses and goggles as well as Blue laser safety window with laser safety sertifications.
The Laser in the post image is a 6W optical power range blue laser diode (Opt Lasers PLH3D-6W-XF) which can be invested with a reasonable price and be sure you get the best quality and best safety features found on the market. The linked tools covers everything you need to get started with most of the CNC controllers available but make sure to check if your cnc controller upgrade kit is available.
In my case i have a Planet-CNC MK3/4 controller which worked out of the box with the linked upgrade kit. In matter of fact, it could also have worked only with the laser module, but then overall safety would need to be thought of really carefully so i recommend starting with the full upgrade kit to be on the SAFE side!