This is a high-performance replacement cordless battery for the Panasonic KXA40, guaranteed to meet or exceed the OEM specifications of your original. The cordless battery is 2.64 x 2.23 x 0.72 inches with an output of 4.8 volts. The chemistry is at 600mAH capacity. Manufactured by Empire Scientific, model number CPB-445. 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.