1.four size:55mm,60mm,65mm,70mm 2.material:CR39 lens 3.round top,flat top are available ... Bifocal lensSemi-Finished lensTechnical data:1.Material:CR- ... UV protection -option HEMW(ITO)Coatedspecifications of 1.8 Semi-Finished lens single-vision65mm/70mm,50base-1000baseSpecifications ... quality(A degree/B degree) CR-39 1.8 lens&bifocal lens&semi-finished lens