The Nikon illuminated reticle can be utilized in 3 ways. First, they can be illuminated in red for extreme contrast against a wide variety of backgrounds in low light. Second, they can be illuminated in green, providing superior illumination in brighter conditions or against some unique backgrounds. Finally, the illumination can be turned off and the reticles can be used just as one would use the standard, non-illuminated counterpart. Features: 95% light transmission, Fully multicoated lenses for unsurpassed light transmission/contrast, Nikon's famous super-high resolution lenses, One-piece main body tube construction, 100% Waterproof/Fogproof/Shockproof, 1/4-minute click reticle handturn adjustments, Lifetime Full Warranty, Quick Focus Eyepiece. Specs: Actual Magnification : 3.5x-10x, Objective Diameter: 50mm, Exit Pupil: 14.3-5mm, Eye Relief: 3.9-3.8", FOV @ 100yds: 25.5-8.9', Tube Diameter: 1", Length: 13.9", Weight: 17.6oz, Adjustment Graduation: 1/4 MOA, Max Internal Adjustment: 45 MOA, Parallax Setting: 100yds. Options: Duplex or Mildot reticle, matte finish