The Trijicon ACOG (Advanced Combat Optical Gunsight) series was designed to be extremely durable and reliable. ACOG sights combine traditional, precise distance marksmanship with CQB speed. Every feature of an ACOG scope was chosen for a single purpose: to provide increased hit potential in all lighting conditions. The 4x32 ACOG scope features a dual-illuminated red crosshair reticle that uses fiber optics and tritium for a bright aiming point in all light conditions. The ranging reticle also allows for bullet drop compensation out to 600 meters without any manual adjustments. Another important feature of the 4x32 ACOG sight is that it comes equipped with the Trijicon TA51 mount. The TA51 mount is a thumbscrew Picatinny mount manufactured by Trijicon specifically for your ACOG sight. When it comes to optics, you can trust Trijicon and their brilliant aiming solutions.