This U10 tactical flashlight can be used as a standard flashlight or with a pressure switch. The pressure switch has two buttons; one is a standard on/off toggle and the other is a press-and-hold power button. The flashlight itself also has a button to toggle different lighting modes (low/med/high).Comes with a rifle barrel mount,it is perfect for any rail system.If you want an affordable unit for night time home defense light, this is an excellent choice.