... -docking station for iPhone 4 & Ipod 2.portable stereo mini speaker 3.fm fadio, usb and TF card 4.excellent sound effects ... inch(external diameter 45mm) magnetic resistant 4 OhmsLine in: configure 3.5mm stereo's plugs,U Disk,SD/MMC CardPower supply ... ,5V/1000mA AC ADAPTER,PC USBLithium battery input: 3.7VCharge voltage: 4.2-5VBattery capacity:500mAh Mini speaker for Ipod & Iphone 4