The next significant feature is the rate of fire selector. This allows you to discharge one to four rounds with each click on the trigger button. This can give you a really big advantage in a situation where timing is everything. There are three selections for this setting. For one shot the scroll wheel is not lit up, for two shots the wheel glows red, for three shots the wheel glows blue and for four shots, the wheel mixes the red and blue to make purple, but as you can see, the blue LED outshines the red, so it looks more blue-ish (last picture).