Hello, this is John Chan from LuoYang HengRen Optoelectronic Co.,Ltd..We make lenses with diameter from 1.0mm to 300mm by optical glass or optical crystals, such as BK7, fused silica, sapphire, and CaF2. Our standard lens has the following specifications: Material: grade A BK7, fused silica, sapphire, or CaF2 Diameter tolerance: +0.0, -0.12mm Paraxial focal length tolerance: ±2% Centralization: 3arcmin Clear aperture: >85% Surface figure: 1/2 at 632.8nm Surface quality: 60/40 scratch/dig Bevel: 0.25mm x 45° Coating: uncoated or coated upon requests We supply standard lens (please visit our website for standard lenses) and customized or OEM lenses upon customers' requests. We have advanced measurement instruments, and a trioptic lens measurement system, to ensure accuracy of each lens.