Nikon Binoculars Yu 4X10D CF Champaign Gold magnification (twice) :4 object lens Effective diameter (mm) : 10 real-field-of-view (degree) : 10.0 appearance field-of-view (degree) : 38.6 (40.0) Field of view (m) in 1000 m : Diameter of 175 pupils (mm) : 2.5 brightness : [ 6.3 ] Eire Leaf (mm) :13.7 -- the shortest focal length (m) : 1.2 Mass (weight) (g) : 65 height (mm) : 52 Width (mm) *1 : 93 Interpupillary-distance adjustable range (mm) : Apparent field of view which a 57~72 *1 strap through part removes: It is a new notation numerical value based on ISO14132-1:2002. () Inside is a notation numerical value conventionally. Shortest focal length: In the case of the emmetropic eye which has not adjusted