This is a high-performance replacement laptop battery for the Compaq Presario CQ42-201AU, guaranteed to meet or exceed the OEM specifications of your original. The laptop battery is 8.07 x 2.42 x 1.49 inches with an output of 10.8 volts. The chemistry is LI-ION at 8800mAH capacity. Manufactured by Empire Scientific, model number LTLI-9226-8.8. 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.