Vortex Diamondback Rifle Scopes feature solid, one-piece aircraft grade aluminum alloy construction which makes them very strong and more resistant to even the heaviest recoil. They are purged with Argon gas which eliminates internal fogging and retains its protective properties over a wide temperature range. Optics are fully multi-coated and transmit 91% of available light. The windage and elevation dials also pop-up for fast and easy adjustments. Protective lens covers are included.