BARSKA 2.5x15x56 AR6 Riflescope Field of view (ft at 100yds/m at 100m): 12.4/37.20 at 2.5X, 2.1/6.28 at 15X Exit pupil (mm): 3.5at2.5x Eye relief: 3.7" Reticle: Mil Dot Tube Diameter: 1" Magnification 2.5-15x . Objective Lens 56mm Exit Pupil 3.5@2.5x, 13.2@15x . Eye Relief 3.7 Inches Adjustment Knob Side Parallax Adjustments, Windage and Elevation adjustments Reticle Mil Dot Click Value 1/4" . Tube Diameter: 1 inch