Enjoy good sound in a sleek, portable design with Rolsen RBM-413! Use this wireless devise just about anywhere--from the kitchen or living room to an office or countryside. It can even be taken along to the beach when relaxing in the summer sunshine with friends. The device has FM-radio function, MicroSD/SD slot, USB slot and comes with line-in capability, which allows you to connect your non-Bluetooth-enabled devices directly to the speaker. Lithium-ion rechargeable battery provides up to 4 hours of wireless play - no need to buy batteries. A USB to micro-USB cord (included) makes it easy to recharge the battery. Simply connect the USB to your computer or wall adapter.