This is a high-performance replacement cellular battery for the Plantronics CS540, guaranteed to meet or exceed the OEM specifications of your original. The cellular battery is 0.835 x 0.56 x 0.198 inches with an output of 3.7 volts. The chemistry is LI-POL at 140mAH capacity. Manufactured by Empire Scientific, model number CPP-540. 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.