This is a high-performance replacement cellular battery for the T-Mobile DASH, guaranteed to meet or exceed the OEM specifications of your original. The cellular battery is 2.2 x 1.44 x 0.2 inches with an output of 3.7 volts. The chemistry is Li-Ion at 900mAH capacity. Manufactured by Empire Scientific, model number BLI-1105-.9. 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.