Magalasi Opangira Magalasi a 6, Dia. Zamgululi

Choikidwacho chili ndi mitundu isanu ndi umodzi yofunikira kwambiri ya mandala., Imaphatikizapo chimodzi mwazinthu izi: plano -concave, convex-concave, Double concave, concave-convex, plano-convex, ndi double convex. ? Makulidwe a mandala ndi 50-mm approx.