The 800 Lumens LED Lantern with BatteryGuard™ stops battery drain so you'll have power when you need it most. Conventional lanterns experience residual power drain as long as batteries are connected to the circuit. With BatteryGuard, batteries are automatically disengaged from the circuit when the lantern is turned off to extend their life by as much as 25%. It also reduces the chance of damaging corrosion so batteries can be stored in the device for years (up to their inherent shelf life). Additional features include a rotating dial to switch between high, medium, and low modes, up to 30 hours runtime on high using 4 D batteries (sold separately), water resistance, impact resistance up to 2 meters (on dirt), and lifetime LED bulbs that never need replacing. No matter the situation, this BatteryGuard lantern with a 15-meter beam gives you Power When You Need It™.