Always Be Prepared. Optimized for use in SureFire flashlights, SureFire 123A high-performance lithium batteries pack a lot of power into a very small package. And unlike alkaline batteries, SureFire batteries have a 10-year shelf life, which means they will be ready when you need them, every time. Trust in the power and durability of SureFire batteries. Features: The best 123A lithium batteries available, bar none 123As outperform alkaline batteries 10-year shelf life - they're ready when you need them