This is a high-performance replacement cellular battery for the Samsung SGH-M919, guaranteed to meet or exceed the OEM specifications of your original. The cellular battery is 2.48 x 2.25 x 0.425 inches with an output of 3.8 volts. The chemistry is LI-ION at 5200mAH capacity. Manufactured by Empire Scientific, model number BLI-1341-5.2B. 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.