Model: 20X50 Prism Type: BAK-4 Eyepiece diameter: 22MM (large eyepiece design) Objective lens diameter: 50mm Small focusing distance: 5.0m Exit Pupil Diameter: 4.1mm Viewing distance: 17mm Relative brightness: 25.00 This 20x50 High Powered Bonocular Telescope is a portable travel telescope that makes a great addition to any outdoor kit. With high grade multi coated lenses, it delivers a fantastic viewing experience wherever you go and allows you to see true to life color definition without impairing your visual experience. This Military Grade Telescope features a Large BAK-4 prism and multi-coated lens to guarantee superior light transmission that enables a brighter and clearer view and delivers true to life color definition. To adjust the focal length easily, this HD Zoom Optical Lens is constructed with Central Focus Knob for easy, precise adjustments. It is quipped with large 50mm objective diameter which means it can gather more light which is particularly important in poor light conditions, such as bird watching at dusk. Thanks to its 20x magnification, objects will appear 20 times closer than with the naked eye. Made for the outdoor, it boasts of a stylish rubber covered aluminum body for optimum protection from rough handling. Designed with ergonomic thumb indents and finger ridges for extra non-slip comfort and ease of use. Slip it inside your rucksack with the rest of your travel gear for your outdoor expedition. Brand No Brand SKU 100106318_NP-1020358446 Model other