1.Lightweight, elegant flip-up design is convenient, comforable, and easy to use 2.Ultra-wide field of view without distortion keeps your eyes from getting tired. Anti-fog Lens 3.Prism Optics system provides extra long depth of field even at higher magnifications 4.With high definition optics,(multi-layer anti-reflection coating) you will experince the best resolution,field of vision,and depth of vision.Will not feel any uncomfortable even if all day working 5.Other viewing distances available, including custom distances, see description for details