CO2 laser lens 20mm diameter focal length 63.5mm - 2.5 inches USA The lens made of ZnSe PVD material guarantees very good cutting performance. If your old lens is cracked, scratched and the laser does not work properly ( does not cut plywood, does not cut parts), it is time to replace the optics with a new one. The anti-reflective coating found on both sides of the lens minimizes the loss of laser optics. It is resistant to high temperatures that are generated during laser operation. Material: ZnSe PVD Application: CO2 laser MADE IN USA