Named after the Eastern and Western species of rattlesnake, the Vortex Diamondback Spotting Scope series excels in low light, producing images with excellent clarity, detail, and edge-to-edge sharpness. The superb optical quality is thanks to the use of XR fully multi-coated lenses, and a porro prism with dielectric prism coatings. Additional features include an adjustable eyecup, a built-in sunshade, and a rotating tripod ring. All of the Spotting Scopes in the Diamondback Series come standard with a rubberized outer shell that helps protect both external and internal components from shock damage, as well as the proprietary Armortek lens coating to protect the optics from dirt, oil, and other forms of debris.