Specification of our achromatic lens as follow: * Material: BK7 and ZF2( or according to your request) * Dia.: + 0/ -0.05 * Center thickness tolerance: + / -0.1 * Surface quality: 60-40 * Surface figure: 0.5-0.2 * Centration < 3arc min * Chamfer: 0.1-0.25* 45 degrees * Design wavelength: 486.1mm, 587.6mm, 656.3mm ( the parameter is demision of nomal lens, so specification will be changed according to different demision and material)