This is a high-performance replacement cellular battery for the Samsung SPH-M840, guaranteed to meet or exceed the OEM specifications of your original. The cellular battery is 2.57 x 1.87 x 0.189 inches with an output of 3.7 volts. The chemistry is LI-ION at 1500mAH capacity. Manufactured by Empire Scientific, model number BLI-1307-1.5. 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.