Znse protective window is used to CO2 laser cutting machine,there is twp places to fix protective window, one is outside laser tube, another is below the focus lens to prevent the dirt gas or oil pollute the lens extaend the life span.

Normally the protective window diameter is a little bigger or the same as laser tube output and focus lens,the common size is 19mm 20mm 25mm 25.4mm ,38.1mm, 50.8mm if you need other size we can OEM for you.

Due to the special usages protective window,it requires the material with high transmissivity low absorption,so CVD znse is the best choise with the all infrared material,with a proper coating. Znse window will make energy small loss and extend the life span of other lens.