You should first insert the CR2 lithium battery and close the battery door. Your Viridian slides onto your gun’s rail and smoothly integrates with your trigger guard for an excellent fit. To turn your Viridian on press either of the ambidextrous rubber tactile buttons and release. Pressing both buttons while your Viridian Green Laser is on will cycle through the four different modes of operation. Press both buttons and release each time to reach the next mode. Your Viridian will remember the mode selection for the next use. Pressing either button for more than three quarters of a second will activate your Viridian in momentary. Once you release the button, your Viridian will turn off.