�� Specifications:
�� Material: BK7 Grade A,optical glass
�� Dimension Tolerance(��): +0.0, -0.2 mm
�� Dimension Tolerance(h): +/-0.3 mm
�� Clear Aperture: >80%
�� Deviation: 180��+/-3 arc sec
�� Flatness: ��/4 @632.8 nm on big surface
�� ��/10 @632.8 nm on other surface
�� Surface Quality: 60-40 scratch and dig
�� Wavefront Distortion: ��/2 @632.8
�� Protective Bevel