Vanguard Endeavor RS 4-12x40 Riflescope with Duplex Reticle Premium HOYA ED Glass ensures crisp and clear target viewing and eliminates color aberration Single tube construction from high grade T6061 aluminum makes Endeavor RS scopes extremely durable and ready for any situation Multi-coated optics provide superior light transmission in low-light conditions Nitrogen purged to eliminate optics fogging due to temperature changes Vanguard's Premium Lifetime Warranty