This is a high-performance replacement cordless battery for the Sennheiser RI410, guaranteed to meet or exceed the OEM specifications of your original. The cordless battery is 1.26 x 0.975 x 0.365 inches with an output of 3.6 volts. The chemistry is Li-Pol at 140mAH capacity. Manufactured by Empire Scientific, model number CPP-523. 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.