10-30x60mm Colorado Zoom Binoculars are a highly versatile pair of binoculars that will give you pristine mid- to long-range viewing with smooth focusing capabilities, powerful optics, and a rugged body. These binoculars are equipped with a reverse porro prism system, feature a wide magnification range from 10x to 30x, allowing you to view distant objects and nearby vistas with the same high-definition clarity. Fully coated optics combined with the BK-7 reverse porro prism to make these binoculars excellent for use in low-light conditions, giving you optimum brightness. These binoculars offer a greater depth of field and a wider field of view, allowing you to see more at once and in greater detail. Zooming in is easy, with the large center focus knob and right eye diopter make adjustments quick and smooth. The fold-down eyecups allow even glasses wearers to use the binoculars in comfort. Broaden your horizons with the extreme magnification power of the Colorado 10-30x60 Center Focus Zoom Binoculars. -Magnification: 10-30x -Objective Diameter (mm): 60 -Angle Of View (Degree): 3.6˚@10x; 2˚@30x -Field Of View (F.O.V) (feet): 189 @ 10x, 105 @30x -Field Of View (F.O.V) (m): 63 @ 10x, 35@ 30x -Close Focusing Dist (m): 32.8/10 -Exit Pupil (mm): 6@10x; 2@30x -Relative Brightness: 36@10x; 16@30x -Eye Relief (mm): 14@10x; 12@30x -Lens Coating: Fully Coated -Lens Color: Blue -Prism Type: Porro -Prism Coating: BAK-7 -Focusing System: Center -Body Material: Rubber -Finish / Color: Black -Eyecups: Rubber Fold down -Warranty: Limited Lifetime.