Marine binoculars area of use wildlife watching watersports magnification 7 x lens diameter 50 mm prism system porro suitable for intermediate expert exit pupil diameter 714 mm field of view in 1000 m 145 m twilight factor 187 relative brightness 51 02 viewing straight binocular coating diamond marine coating weight 1 190 g material thermoplastic colour black additional functions compass operating temperature 40 80c included in delivery