The ACOG is internally-adjustable, compact telescopic sights with Tritium-illuminated reticle patterns for use in low light or at night. It combines traditional, precise distance marksmanship with close-in aiming speed. This model is 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. Includes a thumbscrew flattop adaptor, 5.5X50 Scopecoat, LENSPEN, lanyard assembly for adjuster caps, Trijicon logo sticker, ACOG manual and warranty card. Length 12" Proofs Fog/Shock/Waterproof Series Riflescope Weight 25.60 oz Reticle Illuminated Red Chevron .223/5.56 BDC Objective 50mm Eye Relief 2.20" Coating Type Waterproof, Fogproof, Shockproof Field Of View 18.40 ft @ 100 yds Magnification 5.5x Optic Coating Multi-Coated Exit Pupil Range 5yds-Infinity Parallax Adjustment 5yds-Infinity