Trijicon AccuPoint 1-6x24 Riflescope, 30 mm Tube Superior Quality Lenses: Multi-coated lenses provide superior clarity and light gathering capabilities with zero distortion Battery-Free Illumination: Fiber optic technology automatically adjusts the brightness level and contrast of the reticle aiming point to available light conditions and a tritium phosphor lamp illuminates the reticle in low to no light Aircraft-Grade Aluminum Housing: All-weather rugged construction protects against the toughest elements Second Focal Plane Reticle: Reticle size remains constant as magnification increases which provides a more exact aiming point at higher magnifications Zero Forward Emission: The illuminated reticle doesnt project any illumination from the objective lens