Frontier HD X models feature HawkeOs 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. Dielectric Coatings. High Resolution Phase Corrected BAK-4 Roof Prisms. Water Repellent Lens Coatings. Magnesium Alloy Chassis. Focus From 2.5m. Replaceable Twist-Up Eye Cups With Position Stops. Stay-On Lens Covers