This is a high-performance replacement cellular battery for the Apple IPHONE 4 EXTERNAL BATTERY CASE, guaranteed to meet or exceed the OEM specifications of your original. The cellular battery is 4.99 x 2.42 x 0.59 inches with an output of 5 volts. The chemistry is LI-POL at 1500mAH capacity. Manufactured by Empire Scientific, model number EBC-001-1.5B. 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.