Material: High class CVD ZnSe material (US II-VI). High-quality materials ensure more stable laser system; excellent High-Power density endurance. Compatible power: 40W-200W. Diameter: 20mm/0.79"; Focal Length:63.5mm/2.5"; Thickness:2.0-2.2mm/0.08"; Transmittance: ≥99.8%. Exquisite Coating Process: Superb Double-sided solid coating, increase service life, precision slicing, polishing and grinding process, Reduced laser loss, wiping resistant, high temperature resistance, excellent optical properties, high working efficiency. High efficiency: CVD ZnSe Laser Focus Lens has smaller focusing spot size, the energy is more concentrated, making the CO2 laser engraving, cutting machine more efficient. Usage: CO2 replacement laser lens are mainly used in CO2 laser engraving and cutting well. Lens Shape: Plano-convex( some meniscus shape may mixed together when manufacturing, but it is the same effect as Plano-convex shape).