Vortex Diamondback 3-9x40 Riflescope BDC (BK-01-BDC)Diamondback riflescopes are loaded with features. First, the solid one piece aircraft grade aluminum alloy construction makes the Diamondback riflescope virtually indestructible and highly resistant to magnum recoil. Argon purging puts waterproof and fogproof performance on the agenda, and advanced fully multi coated optics raise an eyebrow when crystal clear, tack sharp images appear in the crosshairs. Look for all this and more in a riflescope you'd