Vixen Optics Professional Astronomy Terrestrial Observation Standard Porro Prism Binocular SZR 16x50 ZCF Porro-Prism. Leatherette Armor Surface. Coated Optics. Includes nylon case and strap. BK7 Prism. Magnification 16X. Aperture: 50 mm. Real Field of View 4.2 Deg. Exit Pupil: 7.14 mm. Close Focus: 12 m. Eye Relief 9.7 m. Coating: Multi Coated Optics. Rubber Armor. Dimensions: 8"Lx8.5"Wx2.5"H. Weight: 1 3/4 lbs.