Normal specification of our infrared lenses as follow:
*Material ZnSe, Si, Ge, CaF2, MgF2, FS etc.
*Dimension tolerance +/-0.20mm
*Thickness tolerance +/-0.20mm
*Surface Quality 60-40
*Flatness λ/4 at 633nm
*Clear Aperture 80%
*Crystals directional precision 5 min
*Bevel 0.3+/-0.20mmx45 degree
*Coating Optional