The Nitecore NL2145 is the latest 21700 battery from Nitecore. With lithium-ion chemistry, this battery is designed for extended use in the New P12. The high voltage and intense 4500mAh capacity make this battery a powerhouse in any flashlight, granting extended runtimes and high outputs. This battery has multiple internal and external safety measures including built-in PTC to inhibit high current surges, pressure relief valves to circumvent rapid temperature increases, durable metallic film coating to guard against abrasions, and nickel-plated stainless steel protectors to ensure high impact resistance, good electrical conductivity, and oxidation resistance. The NL2145 is made with the Nitecore standard in mind, ensuring that this battery will power your favorite flashlights to their specifications.