Common Specifications:

Material :BK7, fine annealed

Focal Length (f): ±2%

Dimensions: ±0.2%

Center Thickness: ±0.2mm

Surface Accuracy: L:0.5λ ; W: 1λ

Surface Quality: 60-40 scratch-dig

Clear Aperture: >80%

Centration: 3 arc minutes

Bevel: 0.25 mm x 45°