This is a high-performance replacement cellular battery for the Apple MD277LL/A, guaranteed to meet or exceed the OEM specifications of your original. The cellular battery is 3.18 x 1.24 x 0.174 inches with an output of 3.7 volts. The chemistry is LI-POL at 1432mAH capacity. Manufactured by Empire Scientific, model number BLP-1276-1.4. 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.