This is a high-performance replacement cellular battery for the Nokia 5310, guaranteed to meet or exceed the OEM specifications of your original. The cellular battery is 2.14 x 1.33 x 0.18 inches with an output of 3.7 volts. The chemistry is Li-Ion at 600mAH capacity. Manufactured by Empire Scientific, model number BLI-1140-.6. 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.