DetailsSerious optical performance in a slim, in-line binocular that's a pleasure to take into the field. Waterproof/fogproof. Proprietary nitrogen fill process, Synergy built. Smooth focusing, cold mirror coated prisms, twist up eyecups, armor coated, rugged and waterproof. L-Coat BAK4 Prisms. Slim, In-Line design. Close focus distance of 10 feet, ergonomic design, phase coated, diopter focus, BAK 4 prisms.