The LG-401G green laser sight for 1911 pistols combines Crimson Trace's celebrated Lasergrips® platform with the visible advantages of green laser technology. Using the smallest laser green laser diode available" the LG-401G emits a powerful green beam yet still provides over two hours of run time on (4) #2016 batteries. The LG-401G utilizes Crimson Trace's famed Instinctive Activation™ technology - meaning that when the pistol is held in a normal firing grip" the laser sight is activated. A Master On/Off switch allows the shooter to completely power down the unit for range training without the laser. Green Lasergrips® set a new standard in 1911 green laser technology. This product is not compatible with ambidextrous safety levers