Vortex Optics V105RT-HD Vortex Viper HD 10x50 Tactical Binocular, R/T Ranging Reticle, MRAD Dielectric Prism coatings: multi-layer Prism coatings provide bright, clear, color-accurate images Roof Prism: valued for greater durability and a more compact size Phase correction: coating on Roof Prism models enhances resolution and contrast Field of View: 278 feet/1000 yards|5.3 degrees Close Focus: 8.2 feet