Athlon Optics , Ares , Spotting Scope , 20-60 x 85 ED , Apochromatic lenses System gives you the result of images which have greater contrast, sharpness and color definition ED Glass gives you an image with little or no chromatic fringe so the final result brings a clearer and sharper image to your eyes Esp dielectric coating is a multi layer Prism coating that reflects over 99% of the light to your eyes bringing you a clear, bright image that displays accurate color reproduction Advanced fully multi-coated lenses gives you better light transmission to bring optimum brightness and true color across the entire light Spectrum. Eye Relief - 0.75-0.63 inches Argon purging gives you better waterproofing and thermal stability.The lens are then treated externally with our XPL coating to withstand dirt, oil and grime of constant use as well as standing up to harshest weather conditions .