This round double convex optical glass lens is designed for physics and educational uses. It is approximately 2" (50mm) diameter and 15.5mm thick. Note, thickness varies as they are not designed to be consistent in that respect. Because of their educational use design, there may be minor imperfections that do not affect physical function. 50mm Focal Length

This round double convex optical glass lens is designed for physics and educational uses. It is approximately 2" (50mm) diameter and 15.5mm thick. Note, thickness varies as they are not designed to be consistent in that respect. Because of their educational use design, there may be minor imperfections that do not affect physical function. 50mm Focal Length Round double convex optical glass lens designed for physics and educational uses.