The HR-MQN10A4N package has rechargeable batteries utilizing eneloop XX technology, delivering 2500mAh of long lasting performance for high power applications. XX batteries are the perfect choice for powering high current consuming devices such as cordless phones, LED flashlights, photo strobe flash units, wireless keyboards / mice, game controllers, radio controlled toys and thousands of other battery operated products. Eneloop XX batteries are engineered to excel in extreme conditions where high power performance is needed. These Nickel Metal Hydride batteries retain up to 75% of their capacity even after one full year of storage. Unlike regular alkaline batteries which can only be used once the XX batteries can be recharged up to 500 times. They are pre-charged at the factory using solar power and can be used immediately out of the package. eneloop XX batteries deliver reliable, high power battery performance when, and where, you need it most! The 4 position Ni-MH battery charger has worldwide voltage capabilities and has a retractable AC plug to easily connect to an AC outlet. It is ideal for use at home, in the office, or on the road. The sleek, black charger provides a convenient and efficient way to charge 4AA, 4AAA or 2AA and 2AAA eneloop batteries. Charging indicator lights will flash while charging and then will remain on once the battery charging has been completed. There is one LED light for each pair of batteries installed. Batteries must be charged in pairs.