6 element design in three groups giving a respectable 55+ degree field of view. All glass optics are unused, fully coated. Exit aperture (clear eye lens diameter) is 36mm and eye relief is 20mm. Barrel is threaded for filters, considerably light-weight for its size (about 9 ounces). Nice, sharp, edge to edge clear, color corrected images with a very flat field. Wollensak, quality optics since 1899! Super low price!
