The optical and mechanical tolerances of these riflescopes are so close and tight that you get unparalled accuracy and consistency. The lenses are pure grades of optical glass, ground and polished to exacting standards for a perfect optical curve. They are then chemically multi-coated (including the outer surface) to eliminate glare and reflections and to provide maximum light transmission. Finger-adjustable, 1/8"-MOA windage and elevation adjustments are oversized so they can be manipulated even when wearing gloves. The adjustments are so precise you can be sure each click will be consistent with the others. And the system is strong enough to hold zero through years of shooting. The super-smooth zoom mechanism stays on target when changing power, the tracking cells which hold the lenses fit into the tube with absolute minimum tolerances. They won't shift under recoil, so your point of impact stays solid. The nitrogen-filled scope chambers are multiple sealed which ensures they stay water-, fog- and shockproof. An adjustable objective eliminates parallax problems. Each scope includes two (3" and 5") sunshades that can be screwed together for extra glare reduction. The generous eye relief reduces tunnel vision. Includes screw-on metal dust caps.