This is a high-performance replacement two-way battery for the Vertex VX351, guaranteed to meet or exceed the OEM specifications of your original. The two-way battery is 3.89 x 0.83 x 2.21 inches with an output of 7.4 volts. The chemistry is LI-ION at 2000mAH capacity. Manufactured by Empire Scientific, model number BLI-FNB95. 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.