SWFA SS 20x42 Tactical Riflescope Mil-Quad Reticle 1/10 Mil Adjustments Rear Focus SS20X42MQ Matte Black Finish, 30mm Tube, Rear parallax Adjustment Exposed finger adjustable turrets with 5 Mil's per revolution In sub-zero temperatures or searing desert heat (-50 degrees to +130 degrees Fahrenheit, and altitudes of 30,000 feet to depths of 15 feet in salt water) the waterproof, shockproof, fogproof SS performs. Made of lightweight aluminum but strong as steel, it has superior multicoated optics for maximum light transmission. Built to NATO specs