Pentax 5.5x Super Multi Coated Magnifier Loupe with Transparency Stand large aperture optical design (1.0 inch - 49mm) Super Multi Coating lens elements (SMC) Wide perspective covering almost entire image area of 645 camera format Actual Image Area: 1.7 inch (43mm ) Helicoid-type diopter adjuster (-4D - +1D) Extra Long eye relief - 0.6 inch (14mm)