This is a high-performance replacement cordless battery for the V-tech DS6421, guaranteed to meet or exceed the OEM specifications of your original. The cordless battery is 2.1 x 0.66 x 0.33 inches with an output of 2.4 volts. The chemistry is NiMH at 500mAH capacity. Manufactured by Empire Scientific, model number CPH-518J. 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.