TSO Marlin 10x42 Roof Binocular Black. We find 10 power to be the most versatile magnification for a wide range of uses. Specifications for TSO Marlin 10x42mm Roof Prism Binocular: Manufacturer: TSO Color: Black Magnification: 10 x Objective Lens Diameter: 42 mm Prism System: Roof Prism Material: BK-7 Eye Relief: 14.7 mm Exit Pupil: 4.2 in Field of View Linear: 293 ft at 1000 yds Field of View Angle: 5.7 degrees Binoculars Focus System: Manually Adjustable Interpupillary Distance: 57 - 76 mm Close Focus: 23 ft Weight: 23.8 oz Fabric/Material: Rubber Width: 5.1 in Package Contents: TSO Marlin 10x42 Roof Binocular TSO T111001: Marlin 10x42 Roof Binocular Black