Vortex Optics designed the Spitfire Prism Sight to be used with an AR platform firearm for quick target acquisition in close-to-medium range shooting situations. This ultra-compact sight features multi-coated lenses with a prism-based design delivering a sharp image of the EBR-556B reticle while the rugged design of the Spitfire ensures this prism sight is waterproof, fogproof, and shockproof. The illuminated red/green reticle has five levels of brightness and has a typical battery life of 250 hours at maximum brightness. The EBR-556B (Enhanced Battle Reticle) is designed for the 5.56x45mm cartridge and provides holdover and ranging references between 0 and 500 yards. If you are looking for a tactical sight for your AR weapon, the Spitfire is sure to do the job. Also includes flip caps and Vortex's VIP Unconditional Lifetime Warranty.