Trijicon TA11F ACOG 3.5x35 Rifle Scope with Red Chevron BAC Reticle includes Trijicon Flat Top Adapter TA51. The ranging reticle of the Trijicon Gunsightis calibrated for 5.56mm (.223 cal) flat-top rifles out to 800 meters. The chevron reticle is designed to be zeroed using the tip at 100 meters. The width of the chevron at the base is 5.53 MOA which is 19" at 300 meters. This allows range estimation for silhouette targets. Trijicon TA11F 3.5 x 35mm ACOG Advanced Combat Optical Gunsights hit fast in any light. The Trijicon ACOG 3.5 x 35 TA11F is an internally-adjustable, compact telescopic sight with tritium illuminated reticle pattern for use in low light or at night. Bindon Aiming Concept (BAC) models feature bright daytime reticles using fiber optics which collect ambient light. Trijicon 3.5x35 ACOGs combine traditional, precise distance marksmanship with close-in aiming speed. Although The Trijicon ACOG 3.5 x 35 TA-11F gas many features which are very advantageous for military use, is was developed by Trijicon without government funding. Designed for use with the M16 family, every feature of its mechanical and optical design was chosen for a single purpose: to provide increased hit potential in all lighting conditions - without failure-prone batteries. Trijicon TA11F ACOG 3.5x35 Red Rifle Scope Specifications: Magnification: 3.5 Objective Size: 35 Bullet Drop Compensator: Yes Length (in): 8.00 Weight (oz): 14 w/o mount Illumination source: Fiber Optics/Tritium Reticle Pattern: Chevron Day Reticle Color: Red Night Reticle Color: Red Calibration: 0.233 Bindon Aiming Concept: Yes Eye Relief (in): 2.40 Exit Pupil (mm): 10.00 Field of View (°): 5.50 Field of View @ 100yrds (ft): 28.90 Adjustment @ 100 yds (clicks/in): 4 Tube Size: N/A Mount: TA51 Mount On/Comes With: Flattop Housing Material Forged: Aluminum