This high-capacity Lithium Ion Rechargeable (LIR) battery is designed for use with Lezyne's performance LED lights. Each battery comes in a weather resistant, machined aluminum tube with rubber end caps for storage and protection from moisture and grime until it is needed. Replacement Lithium Ion Rechargeable 18650 batteries are available separately. All Lezyne batteries are quality tested for capacity and performance before leaving Lezyne's factory. To get the best performance out of Lezyne LED lights, we recommend only using Lezyne batteries.