Laser Lens Set 3Pcs 20 Reflective Mirror 1Pc 50.8 Focusing Lens Engraving Machine Parts 20‑12 Item Type: Laser Lens Set Laser Reflective Mirror: Material: Silicon Coating Band: 10.6μm Diameter Tolerance: +0/-0.1mm Thickness Tolerance: ±0.1mm Surface Type: λ/2per1in Dia Surface Quality: 40-20 Diameter: Approx. 20mm / 0.8in Thickness: Approx. 3mm / 0.1in Applicable Power: 60W-300W (high power) Laser Focusing Lens: Material: Zinc Selenide Focal Length: Approx. 50.8mm / 2in Diameter: Approx. 12mm / 0.5in Thickness: Approx. 2mm / 0.1in Scope of Application: Laser focusing lens is widely used in laser processing and is an indispensable accessory for laser engraving machine, laser marking machine and laser cutting machine The focusing lens is the optical path accessory of the laser machine. Used to focus the beam after reflecting the lens to achieve the purpose of engraving or cutting How e: 1. For cutting leather, wood boards and other dusty environments, wipe it at least once a day. Use a cotton swab to wipe gently from the inside to the outside. Wait for evaporate before processing. 2. After replacing the focusing lens, you need to fine-tune the focusing lens barrel up and down to see which height is the smallest.