This is a high-performance replacement digital battery for the Nikon D4, guaranteed to meet or exceed the OEM specifications of your original. The digital battery is 3 x 2.2 x 1 inches with an output of 10.8 volts. The chemistry is LI-ION at 2600mAH capacity. Manufactured by Empire Scientific, model number BLI-435. 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.