This is a high-performance replacement cordless battery for the BOSE NTA2358, guaranteed to meet or exceed the OEM specifications of your original. The cordless battery is 1.55 x 1.06 x 0.51 inches with an output of 3.7 volts. The chemistry is Li-Ion at 200mAH capacity. Manufactured by Empire Scientific, model number CPL-535. 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.