Sightmark Solitude 10x42 XD Binoculars, their XD (extra low dispersion) glass helps 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 10x42 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-co