All Hawke Frontier Binoculars feature Hawkes new H7 optics, offering stunning high definition viewing with incredible colour control and phase correction. High performance lens coatings and Dielectric Coated prisms ensure the highest level of light transmission. ED X models benefit from Extra-low Dispersion glass for controlled chromatic aberration and the elimination of colour fringing.. Extra-Low Dispersion (ED) Glass. High-quality ED glass combined with fully multi-coated lenses provides optical clarity and precision in all situations. Extra-Low Dispersion (ED) Glass is excellent at reducing the presence of chromatic aberrations (colour-fringing) for a much clearer and reliable viewing experience.. Clear viewing experience, whatever the weather. All Frontier ED X binoculars pass through a strict quality control inspection to ensure all aspects match design intent. They are optically checked for resolution, light transmission and Strehl Ratio for optical image formation. Their resil