The BatteryGuard™ technology on a Coleman® 50M LED Flashlight stops battery drain, so you'll have Power When You Need It™. On a normal flashlight, there is typically some residual drain as long as the batteries are connected to the circuit, even when the light is off. By turning off a BatteryGuard™ flashlight, the batteries are completely disengaged so the flashlight retains it's brightness twice as long and the batteries last 25% longer.