The next generation 21700 rechargeable battery from NITECORE, the NL2150 has an amazing 5000mAh capacity. This powerful battery has improved performance, and superior energy density compared to the previous 18650 batteries. An ideal companion for the NEW P12 tactical flashlight from NITECORE, an extra 21700 is a great back-up battery to have on hand, as more electronic products and NITECORE flashlights will utilize this battery.The NITECORE NL2150 comes with all of the safety features, quality engineering, and more that has made NITECORE a trusted brand for rechargeable Li-ion batteries. Your expensive electronics are safely paired with an NL2150 that features a built-in pressure relief valve, high-temperature resistant design, and built-in safeguards to prevent surges. This protects you from overcharging, over-discharging, as well as short-circuits. The NL2150 is built with premium materials, such as nickel-plated stainless steel connectors for impact resistance, good conductivity, and resistance against oxidation. Safe and reliable, the NL2150 is globally insured and has multiple certifications for electronic use.