... the same time.* Automatically save power sleeping functions, battery life be prolonged.* Super mini build-in receiver, outstanding design.* The ... AAA batteries.* The USB rechargeable cable (5pin) also can be used for some cell phones, mp3, mp4* Operation system: IBM PC , ... with some hard and acuate object within 10 seconds, the receiver light will flash very fast, a few seconds later it will be on ...