Field-tested and approved by the North American Hunting Club, the Sightmark Solitude 8x42 XD Binoculars feature cutting-edge optical technology for stunning sharpness and contrast. their XD (extra low dispersion) glass help correct optical color defects, caused when different light wavelengths do not converge at the same point after passing through optical glass. Engineered with Bak-4 roof prisms, the Sightmark Solitude 8x42 XD Binoculars yield an advanced, straight tube light system, achieving maximum light transmission and optimum brightness. The unit's prisms and lenses are fully broadband multi-coated, improving efficiency at the entIRe range of the visible spectrum. The innovative magnesium bridge makes the unit noncorrosive and durable. Designed to withstand the harsh conditions of the outdoors, the Solitude 8x42 XD Binoculars have a rubber-armored, nitrogen-filled and O-ring sealed body, making them waterproof, fog proof and dust proof. The twist-up, adjustable eye cups provide a comfortable, custom fit, helping to correct eye relief at any viewing position.