Material BK7, Fused Silica,Ge,Si, CaF2. Diameter 5-500mm Surface Figure λ/2 Diameter Tolerance +0.01, -0.01 mm Thickness Tolerance ±0.1 mm Paraxial Focal Length ±2% Centration 90% Surface Quality 60-40 scratch and dig or better Protective Bevel 0.25 mm x 45 ° Coating: Specified by customers
