... -1 are compact and good-looking portable hand held night vision devices.By utilizing their high magnification,excellent optical systems and ... patrol for guards,helpinginvestigation and obtaining evidence etc.Binger Night vision technical specifications:Lens magnification ,x 3 Objective lens diameter,mm ... 100m/110yards,m 19/63 Field of view,deg 18 Focus range,m 1.5 to infinity Exit pupil diameter,mm ...