Are you use eye protection with your CO2?

I have a 60W Chinese red & black, the “windows” are transparent but I coming from a 2.8 jtech and don’t know if is dangerous “see” this invisible laser.

you do not need them. its a different wavelength of light

Assuming the clear window is Acrylic or Polycarbonate, then it will protect your eyes from a CO2 laser. However, if you ever run your machine with the door open you should use eye protection that protects your eyes from the 10.6 μm wavelength.

Always, always wear proper eye protection when anywhere around a laser. You’ve only got the two eyes.
Personally, I don’t care how much shielding your laser has built-in. Wear the glasses.
And I am of course talking about glasses specifically for 10.6 μm.
I realize that acrylic or polycarbonate should protect you, but things happen.

Please don’t ever do this. Honestly, your laser should not fire if the door is open.

All lasers are potentially dangerous.

But, diode lasers, like your JTech, see glass and acrylic as transparent and thus are able to pass through them, so you need safety specs that filter the specific frequency the diode operates at.

Acrylic and glass are opaque to CO2 lasers, which is why we can cut them (or etch them in the case of glass) so you will not burn out your retina wearing basic acrylic safety glasses.

However… being burned is not the only problem. The sheer light pressure from a laser can severely impact your eyes, just as watching the sun could. Wear protection to cut down the amount of light. A good quality pair of dark glasses is enough, or add a sheet of window tint to your machine viewport.

Looking at a bright point source is very tiring on your eyes.

I use these in the workshop:

But in the classroom, I use these, in amber:

Not that the amber works better, but it allows me to easily see who is following the rules and wearing their protection.