This is a high-performance replacement cordless battery for the Microsoft X808059-003, guaranteed to meet or exceed the OEM specifications of your original. The cordless battery is 1.22 x 0.78 x 0.2 inches with an output of 3.7 volts. The chemistry is Li-Pol at 350mAH capacity. Manufactured by Empire Scientific, model number CPP-532. 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.