LSKCSH II-VI USA ZnSe Focus Lens Dia. 20mm FL50.8mm-63.5mm 2-2.5'' for Co2 Laser Engraving Cutting Machine Wholesale Agents want cloudray ii vi znse focal meniscus lens laser engraving cutting machine optical lens dia 20mm fl 50 8mm 263 5mm 2 5101 6mm 4