Magnification Factor: 2.5X Barrel Size: 1.25" (31.7mm) Optical layout 3 element APO design (air-spaced) Clear aperture 23mm Coating: fully multi-coated Blackened Lens Edges: Yes. For suppression of internal reflections Mechanical quality all design. Short length Clamp mechanism precise lock by brass compression ring Weight: 107g/3.77oz