This is a high-performance replacement laptop battery for the Dell Latitude D420, guaranteed to meet or exceed the OEM specifications of your original. The laptop battery is 10.8 x 3.14 x 0.58 inches with an output of 11.1 volts. The chemistry is LI-ION at 3600mAH capacity. Manufactured by Empire Scientific, model number LTLI-9200-3.6. 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.