The Sightmark Core TX 1-4x24DCR .223 .308 Dual Caliber Riflescope uses fully multi-coated optics to provide optimal light transmission in a variety of conditions. Etched glass reticles, in Red or green, are illuminated to deliver optimal shot placement and are durable to withstand years of shooting. �This riflescope features exposed, lockable turrets which help maintain a consistent zero. The turrets are quick and easy to adjust to compensate for bullet drop and windage on the fly. The Core TX 1-4x24DCR is housed in a durable 30mm tube, built from Aircraft grade aluminum. This scope features a Duplex BDC reticle and is calibrated for 223 and 308 ammo.