The new Nitecore NL2140R is a high drain 21700 battery designed for high-performance flashlights and electronic devices. The high 4000mAh capacity ensures long run times and power outputs. This battery has the unique benefit of having a built-in USB-C charging port so you can easily recharge it without needing to buy an external charger. Whether you choose to charge back up with a USB-C cable or Li-ion smart charger, this battery can be recharged 500 times. By reusing drained cells you save money and help the environment! The safe 3-year shelf life makes it perfect for storing as a back-up for when you need it most.