Monocular zoom binoculars area of use travel magnification 25 x lens diameter 25 mm zoom factor 31 times prism system roof exit pupil diameter 1 mm angle of view 21 field of view in 1000 m 37 m twilight factor 25 relative brightness 1 focussing system individual focus viewing straight binocular monocular coating multi coated special features rubber armouring outdoor function waterproof