BK7 windows - as drawing

Material:BK7 grade A optical glass
Size:Dia 3.0~200.0mm x thickness 0.3~60.0mm
Dimension tolerance:0/-0.1mm
Thickness Tolerance:±0.2mm　
Angle tolerance:5 arc sec—3 arc min
Optical parallelism:10arc seconds—1 arc minutes
Flatness(@633nm):λ／10—1λ
Surface quality:80—10scratch and dig
Clear aperture:90％
Coating:available upon request
Bevel 0.25mm x 45