Endeavor ED 8420 Not your typical binoculars, VANGUARD`s top-of-the-line Endeavor ED binoculars deliver sharpness and clarity like never before with exceptional light transmission and remarkable color resolution and contrast. Other features include an ergonomic, open-bridge design for a comfortable use, a wide view angle, BaK4 roof prisms, an anti-reflection coating, large focus adjustment wheel and long eye relief. The magic behind its performance lies in the premium ED glass, which reduces color dispersion to provide high resoltuion colors and clarity. Endeavor ED has BaK4 roof prisms and special lens coatings for unbelievable quality. Nitrogen-charged and o-ring sealed, Endeavor ED is waterproof and fogproof to take on challenging weather conditions. Extra low-dispersion (ED) glass BaK4 roof prisms Waterproof/fogproof Anti-reflection coating Quality warranty：Limited lifetime