Viridian's E SERIES laser sight is specifically designed for the everyday conceal and carry owner. This model specific, trigger guard mounted, laser sight offers the most powerful red laser legally available, delivering rapid target acquisition when you need it most. Features : Easy installation onto the trigger guard of your pistol Ambidextrous on/off button with 5 min auto shut off 25 yard range in daylight and 1 mile at night Constant laser with 6 + hours battery life Easy windage and elevation adjustment Fits the Ruger Security 9 Full-Size and Compact Serial numbers less than E138512 are fitted for Full-Size only