Specifications: 1) Size range: a=b=c 2-50mm 2) Size tolerance: 0.1mm 3) Angle tolerance: 3 4) Surface quality: 60/40 5) Flatness: λ/2 per inch @633nm 6) Bevel: 0.1 - 0.3mm x 45 7) Material: BK7 The specifications will be different according to material and dimensions.