Crimson Trace LG-401G is a green laser that fits most 1911 Full Size models. Grip screws must measure 3-1/16 apart. Does not fit those with ambidextrous safety. Instinctive activation (front) turns on when gripped. Battery life 2 hours. Free batteries for life. Factory adjusted for 50 feet. User adjustable windage and elevation. Get your Crimson Trace laser today!