A good review by Moondog of the Vortex Viper PST Gen2... "The Viper PST Gen 2 is Vortex’s mid-tier LPVO (priced between the Venom and the Razor) and lowest-priced LPVO that offers true daylight bright illumination. You have a choice of an MOA or MILRAD crosshair reticle with calibrated hash marks for long-distance shots. The fiber optic embedded in the reticle provides a red dot bright dot at the center with 10 levels of intensity, powered by a CR2032 battery."