Sightmark's Core TX riflescope uses fully multi-coated lenses to provide optimal light transmission in a variety of conditions. The etched glass reticle is illuminated to deliver optimal shot placement and is durable to withstand years of shooting. The exposed, lockable turrets helps maintain a consistent zero, and the turrets are quick and easy to adjust to compensate for bullet drop and windage on the fly. The durable 30mm tube, is built from aircraft grade aluminum. This scope features a duplex BDC reticle and is calibrated for .223 and .308 ammo.