Optical lens 1) Material: BK7, B270 2) Spherical lens, cylinder lens, window lens, prism lens 3) surface quality: 10/20 Optical lens1) Material: BK7, B2702) Spherical lens, cylinder lens, window lens, prism lens3) Surface quality: 10/204) Diameter: 2mm to 20mm5) Coating is available optical lens