This lens allows indirect viewing (via a mirror) of the angle during glaucoma surgery. Image magnification is 1.0x. It has a custom anti-reflection coating that minimizes unwanted reflections. New and pristine for every patient; no dust, scratches, fingerprints or water marks. Unlike traditional reusable lenses, Katena single use lenses have anti-reflection coatings, except where noted, and no water marks. Each lens comes in a sterile pouch. Single use lenses supplied in quantities of 10.