Specification
The effective focal length (EFL) Tolerance ± 2%
Dimensional tolerances Diameter: +0.000 "-0.005"
Thickness: ± 0.010 "
Edge thickness variation (ETV): <= 0.002 "
Aperture (polished) 90% of the diameter
Surface Accuracy (radial deviation degree / irregularity) @ 0.63μm
Plane side: a striped stripes /0.5
Convex side: With the radius changes
Surface Quality 20-10
Antireflection film reflectivity / surface @ 10.6μm <= 0.20%
Focal Length: 1"(25.4mm)/1.5”(38.1mm) /2”(50.8mm) /2.5”(63.5mm) /3”(76.2mm) /4”(101.6mm) /5”(127mm)
Diameter: 20mm
Tickness: 2mm
Material: ZnSe

Feature
Through high performance, stability, light fine.
Edge polishing, high transmittance, enhanced coating process, durable easy stripping, after focusing, fine spot, cutting and engraving works well.
Widely used in laser processing, laser engraving machine, laser engraving machine, laser marking machine, laser cutting machine indispensable accessories.

NOTE: When installing the focusing lens concave toward work (cutting) material surface, the focal length of the lens should be cut from the surface to the (minimum point of the light play of focus).

Lens Cleaning Note:
1. Be sure to wear rubber gloves or finger to take the lens, because the hands of the dirt and oil droplets will dirty lenses, no gloves, at least Wash and dry your hands, otherwise the lens performance degradation;
2. Gently put the camera lens to the paper, in order to avoid damage to the lens surface.
3. Do not put the lens on a rough or hard surface, the infrared lens is easily scratched.
4. with medical alcohol swab or cotton ball and gently scrub the surface, taking care to avoid forced to scrub. Preferably clockwise or counterclockwise one-time paint intact lenses;
Remember: When cleaning the lens, must be very careful, waiting alcohol dry before use.

Package include
1x ZnSe Focal Len