Nikon 20-45x/25-56x Eyepiece MC for Fieldscope

Magnification: 20-45x when attached to a Fieldscope III or EDIII; 25-56x when attached to a Fieldscope ED82; and 13-30x when attached to a Fieldscope ED50. Angular field of view (Real/degree): 2 at 20x magnification when attached to a Fieldscope III or EDIII; and 1.6 at 25x magnification when attached to Fieldscope ED82; and 3 at 13x magnification when attached to Fieldscope ED50. Angular field of view (Apparent/degree): 38.5 for all models. At 20x magnification when attached to a Fieldscope III or EDIII; at 25x magnification when attached to a Fieldscope ED82; and at 13x magnification when attached to a Fieldscope ED50. Field of view at 1,000m: Approximately 35 m when attached to a Fieldscope III or EDIII at 20x magnification; 28 m when attached to a Fieldscope ED82 at 25x magnification; and 52 m when attached to a Fieldscope ED50 at 13x magnification. Exit pupil: 3 mm at 20x magnification when attached to a Fieldscope III or EDIII; 3.3 mm at 25x magnification when attached to a Fieldscope ED82; and 3.8 mm at 13x magnification when attached to a Fieldscope ED50. Relative brightness: 9 at 20x magnification when attached to a Fieldscope III or EDIII; 10.9 at 25x magnification when attached to a Fieldscope ED82; and 14.4 at 13x magnification when attached to a Fieldscope ED50. Eye relief: 12.9 mm for all models at: 20x magnification when attached to a Fieldscope III or EDIII; 25x magnification when attached to a Fieldscope ED82; and 13x magnification when attached to a Fieldscope ED50. Weight: 100 g.