... power, mini stereo system.5.Adapt to different kinds of device, such as laptop , computer,mp3,mp4,USB disk,SD/MMC memory card,mobile ... 5V-USB Lithium battery: 3.7V 500mA Materials: plasticBuilt-in: SD card,USB decoder, Rechargeable li-ion battery Our company provide good ... can prouduce 5000 pcs per day. Our company specialized in mini speaker, and has offices in Shenzhen . we can print the ...