Material BK7, Fused Silica,Ge,Si, CaF2. Diameter 2-300mm Flatness 1/4lambda or better Diameter Tolerance +0.01, -0.01 mm Thickness Tolerance ±0.1 mm Paraxial Focal Length ±2% Centration 85% Surface Quality 60-40 scratch and dig or better Protective Bevel 0.25 mm x 45° Coating: Specified by customers Angle tolerance +/-30 seconds z
