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 green laser legally available delivering rapid target acquisition when you need it most. 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 60 min battery life Easy windage and elevation adjustmentFits the Ruger 57.Features: Series: E Series LED Light Color: Green Weapon Brand: Ruger Activation: On/Off Only Adjustable: Windage/Elevation Batt. Life (constant): 1 Hour Color: Black Holster Included: No Material: High Strength Thermo Molded Polymer Laser Color: Green Mounting: Trigger Guard Range: Up to 25 yards daylight / 1 mile night Strobing Effect: No Warranty Length: 7 years