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. The best 123A lithium batteries available bar none 123As outperform alkaline batteries 10-year shelf life - they're ready when you need them