This is a high-performance replacement cordless battery for the Plantronics 84598-01, guaranteed to meet or exceed the OEM specifications of your original. The cordless battery is 1.32 x 0.896 x 0.336 inches with an output of 3.7 volts. The chemistry is LI-POL at 140mAH capacity. Manufactured by Empire Scientific, model number CPP-547. 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.