This is a high-performance replacement battery for the ULTRAFIRE 18650 BRC RECHARGEABLE. The battery is 2.69 x 0.71 x 0.71 inches with an output of 3.7 volts. The chemistry is LI-ION at 4000mAH capacity. Manufactured by Utrafire, model number FLB-18650-4.0. We offer a 1 Year Warranty with purchase. See this product elsewhere at a lower price? Call or email us; we have a Price Match Guarantee.