This is a high-performance replacement cellular battery for the Huawei HHB421, guaranteed to meet or exceed the OEM specifications of your original. The cellular battery is 1.93 x 2.17 x 0.205 inches with an output of 3.7 volts. The chemistry is LI-ION at 1300mAH capacity. Manufactured by Empire Scientific, model number BLI-1199-1.3. 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.