At the heart of the Mark 4HD series is Leupold's Professional-Grade Optical System. This system guarantees exceptional clarity, light transmission, and color fidelity. The introduction of an advanced side focus allows for sharp, clear images from 25 yards all the way out past 1,000 yards, ensuring that no detail goes unnoticed. New oversized numbers on the M5C3 elevation dial are easy to see and a tactile ZeroLock windage dial guarantees secure, precise horizontal adjustments (on select models). Whether you're dialing in for a long-range shot or tracking a target in close quarters, you can count on the Mark 4HD to provide you with clear visuals and repeatable accuracy.