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.. High-quality BAK-4 Roof Prisms. High-quality BAK-4 Roof Prisms and Dialectric Coatings ensure exceptional optical performance. The Frontier HD X boast fully multi-coated lenses to enhance clarity and light transmission for better colour fidelity, brightness, and detailed resolution, even in the harshest conditions and challenging environments.. Clear viewing experience, whatever the weather. All Frontier HD 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