Dictaphone Accessories -Dia20mm Focus Lens FL76.2mm 3"" Highlights Generic Brand Dia20mm Focus Lens FL76.2mm 3"" Description: Len dia 20mm, focus length 76.2mm/ 3", anti-reflective coated focal lens for 40-100W laser. Focusing lens is the fixture of the CO2 laser machine, which is used to focus the beam after reflection, to achieve engraving or cutting. This type is improved and updated after collecting feedback from end users. Meniscus type lens, better foucs and meticulous light trajectory. Can withstand high watt density, firm film, less smudges, wipe and scratch resistant. Used for laser processing, suitable for engraving machine, marking machine, cutting machine, etc. Specification: Material: Znse Size: 69x69x18.6mm/2.7x2.7x0.7inch Coating: 10.6um (AR Both Sides) Diameter Tolerance: +0/-0.13mm Center Thickness Tolerance: 0.25mm Focal Length Tolerance : Clear Aperture: >= 90% Diameter Scratch/Dig: 40-20 Surface Accuracy: /2per1""Dia Package includes: 1 Piece Focal Len (Packed in boxes with foamed cotton)