This is a high-performance replacement cellular battery for the Samsung SGH-I577, guaranteed to meet or exceed the OEM specifications of your original. The cellular battery is 2.58 x 1.88 x 0.213 inches with an output of 3.7 volts. The chemistry is LI-ION at 1500mAH capacity. Manufactured by Empire Scientific, model number BLI-1300-1.5. 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.