Digital Mini TF, USB and Radio Speaker. With FM radio function. Response frequency ranges from 87.5 to 108MHz. Support micro SD card and USB flash drive plugging MP3 files music playing. Line in Function. Freely share music with your computer, MP3, Mobile, PC and other audio devices. With LED digital display, show your current situation briefly. New added Clock Alarm function. Offers you much convenience and pratical audio. Battery display. Battery volume symbol on the up right side of LED display, which informs your battery using in a brief sight. Built-in 300mAh lithium battery, recharge it by the accessories attached. Built-in strong magnetic hi-fi loudspeaker works with low consumption and tiny distortion rated amplifier, perfect restore your favorite music. Wrist lanyard makes your outdoor music more cool. Product Size: 52x52x50mm. Material: Metal. (Aluminum Alloy)