High quality unit uses compression ring and has a tapered insert tube for better alignment. Provides images that are right side up and correctly oriented. Aperture is about 25mm. Fully multi-coated. The 1.25" female insert tube on this diagonal will accept 31.5mm or 1.24" of nose piece length before hitting the built in safety stop. If your 1.25" nose piece is longer than this specified distance, the nose piece will not fully insert, though this is rarely an issue.
