Material:------------------------- BK7 Grade A optical glass
Dimension Tolerance: ------+0.0, -0.2 mm
Clear Aperture: -------------->80%
Deviation:--------------------- 180°±3 arc seconds
Flatness: -----------------------l/4 on big surface, l /10 on _other surfaces
Surface Quality:------------- 60-40 scratch and dig
Wavefront Distortion:----- l/2 @633nm
Bevel:------------------------- 0.2 mm to 0.5 mm
Coating on input and output sides:------Uncoated