We supply optical achromatic lens,cemented doulets&triplets. achromatic lens is an achromatic consists of a positive low-index crown glass lens element cemented to a negative high-index flint glass lens element. 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 scrath/dig*surface figure:0. 5-0. 2*centration *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)