Point Blank reticle: Available exclusively on the M-223 1-4x20, this reticle delivers fast, extremely accurate shots from zero out to a 200 yard range “point blank range” for the .223/5.56mm 55-grain polymer tipped round.Eye Box technology: Every model features an impressive 4-time zoom range and four inches of constant, non-critical eye relief. A massive ocular lens delivers a huge, exceptionally bright, high-resolution sight picture. One-piece main body tubes: For minimum weight and maximum strength and durability. Ultra ClearCoat® optical system: Nikon has engineered the entire optical system to provide the shooter with a bright, sharp, incredibly flat sight picture and light transmission up to its theoretical maximum—95%. Smooth zoom control: Magnification reference numbers are viewable from the shooter’s position. Waterproof, fogproof, shockproof: Nitrogen-filled and O-ring sealed.