Practical and often used, the battery may be recharged over 600 times and it usable on any device or equipment that requires AA battery:
Mp3 player, electronic toy, portable radio or speakers, digital camera, flashlight or TV remote.

The LED indicates charging stage of the battery and it has an integrated protection circuit this way ensuring a constant and safe charging.
Red - Charging
Blue - Charged
 

Capacity of the battery is 1450 mAh and you don't need an extra cable for recharging.