Diamondback 8x42 Roof Prism Binoculars By Vortex Optics Product Overview This Rugged binocular is striking in how well it detects life in low light. Huge field of view and the largest in its class and with enhanced fully multi-coated optics and phase corrected prisms and waterproof and fogproof constructions and soft tapered eyecups and and rugged armor. It is all there. Product Specifications: Magnification: 8 x Objective Lens Diameter: 42 mm Eye Relief: 18 mm Exit Pupil: 5.3 mm Linear Field of View: 420 feet/1000 yards Angular Field of View: 8 degrees Close Focus: 4.5 feet Interpupillary Distance: 57-73 mm Height: 5.9 inches Width: 5.6 inches Weight: 25.2 ounces