This is a high-performance replacement digital battery for the Kyocera U4RBK, guaranteed to meet or exceed the OEM specifications of your original. The digital battery is 2.11 x 1.25 x 0.32 inches with an output of 3.7 volts. The chemistry is Li-Ion at 1100mAH capacity. Manufactured by Empire Scientific, model number BLI-276. 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.