This is a high-performance replacement tablet battery for the Apple MD540LL, guaranteed to meet or exceed the OEM specifications of your original. The tablet battery is 5.9 x 3.89 x 0.085 inches with an output of 3.7 volts. The chemistry is LI-POL at 4400mAH capacity. Manufactured by Empire Scientific, model number TLP-010. 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.