XTRONS&reg; 4-in-1 Waterproof Portable Bike LED Light Wireless Bluetooth Speaker Radio FM Microphone SD MP3 Boombox(Color:Black) Features Bluetooth 3.0 4-in-1 Waterproof Bluetooth Bicycle Speaker with Built-in microphone Built-in rechargeable battery Support Micro SD card up to 16GB String antenna design for radio function