The ZULU9 combines superior optical performance with in-the-field utility. High-quality glass, fully multi-coated Spectracoat lenses, and phase-coated Abbe-Konig prisms provide maximum brightness, contrast, and crisp resolution. The ZULU9 performs in the harshest conditions, giving an unmatched performance in inclement weather or rugged terrain. ZULU9 barrels are nitrogen-filled and will not fog in cold, wet weather. Experience the outstanding clarity and day-after-day performance of Sig Sauer with the ZULU9 binos.