Have you ever had experiences that devices are running out of battery while in use? It is disturbing when you are enjoying your MP3 or chatting happily with friends on the phone, etc. Now! USB Power Backup (2400mAh) won't let these situation happen anymore! You can charge your devices in a flash before battery exhausts! It is designed for Handheld PC, Digital Camera, Cellphone, DV, MP3, CD Player, PMP and any other applicable devices.