Built with an extremely durable alloy housing, Monarch ATB is ruggedly constructed for waterproof, fogproof and shockproof performance. Ergonomic styling is mated with a rubber-armored exterior, providing added shock resistance and a firm grip whether wet or dry. All lens and prism elements incorporate Nikon-exclusive Eco-Glass made without the use of arsenic or lead. Prisms feature phase-correction coatings and high-reflection mirror coatings for superior sharpness and resolution. All lenses are fully coated with multiple layers of anti-reflective compounds for maximum light transmission. Large, central focus wheel and adjustable diopter make focus easy to achieve and maintain, even while wearing gloves. Turn-and-slide rubber eyecups, complemented by long eye relief, allow the binoculars to be used comfortably by eyeglass wearers.