Enjoy good sound in a sleek, portable design with Rolsen RBM-413BT! Use the wireless speaker 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.Rolsen RBM-413BT let your smart phones, tablets and any other Bluetooth-enabled device jam. The speaker 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.