Trijicon 4x32 ACOG® Scope, Dual Illuminated Red Horseshoe/Dot M855 RCO Reticle w/ Colt® Knob Thumbscrew Mount

The TA31RCO-M855 is an Advanced Combat Optical Gunsight (ACOG) designed for either the USMC M16A4 weapon system (20” barrel) or the M16M4 (14.5” barrel).