CNCOLETECH CO2 Laser Lens Dia:15mm FL:2 or 50.8mm Laser Mirror CVD ZnSe Focus Focal Lens for CO2 Laser Engraving Cutting Engraver/Cutter 40W-200W

Great for big laser machine

If you have a K40(Chinese) laser cutter and happen to crack your focal lens, thats a good and quick replacement. The quality is the same as the original lens that came out of the box.

I bought a 2.0 focal length CVD IIVI ZnSe lens, 19mm diameter. This lens is thicker at the edge than OEM lenses from universal laser, but it just barely fits, and cuts well enough so far. I bought another one that is listed as plano-convex like the OEM lens, but it is out of spec and too thick to use. The plano convex lens from universal laser is about 2.3mm thick, and 1.75mm thick at the edge. One caveat, which may or may not apply to all replacement lenses, is that you will need to re-calibrate your height adjustments to match the new lens. This one works best for me when I change the calibration from the original lens and set at -0.100 and re calibrate. This makes the table a bit higher, and makes the laser focus tighter than if not calibrated. I made a bunch of test cuts, going first with the calibration that worked for the OEM lens, and moving the table up in 0.050 increments. the kerf got smaller, at .050, smaller still at .100, and then started to get wider at .150 as I raised the table above the ideal focal length.

Excellent. Huge difference between my stock lens and this one.

Works

Helps to focus

Very well packed. Outside plastic bag, then a box with foam, then a smaller plastic bag on the box and then the lens wrapped in tissue

Can’t beat the price point. Lens works great.

smaller than others I have ordered but still worked

These were the perfect upgrade to my stock K40 co2 laser. Received the product when stated by seller and in the condition it was advertised. Will buy from again.