This is a high-performance replacement video battery for the Canon EOS1D, guaranteed to meet or exceed the OEM specifications of your original. The video battery is 4.7 x 3.4 x 0.7 inches with an output of 1.5 volts. The chemistry is NiMH at 2600mAH capacity. Manufactured by Empire Scientific, model number NMH-4/AA. 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.