The Klarus Rechargeable Battery 21GT-50 with a capacity of 5000 mAh is designed to power high-drain devices like flashlights, headlamps, and other electronics. It features a built-in USB port for convenient charging and can be recharged up to 500 times. The battery is made with high-quality materials, including a nickel-plated stainless steel protector, to ensure long-lasting performance and safety. With its high capacity and reliable construction, the Klarus 21GT-50 battery is an excellent choice for powering your gear.