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. Whatever the weapon, from .223 to .50 BMG, the SS handles the recoil. Whatever the target, the SS gives you the best advantage. Made of lightweight aluminum but strong as steel, it has superior multicoated optics for maximum light transmission. Built to NATO specs.