Cool Bass series portable Bluetooth speaker. It offers great quality sound. It is a comprehensive portable Bluetooth speaker with HD sound quality. It can be easily fitted into a backpack, suitcase, handbag, or a travel bag and it is powered by a 1600mAh rechargeable Li-ion battery that offers up to 4 hours of continuous playtime. It is compact and portable, so keep your music pumping wherever you go. You can connect it to your smartphones and tablets and enjoy up to 4 hours of playtime. How to connect FM .Frist click on mode Butten then connect USB cable (it will behave like an FM antenna) in charging jack. To change FM channel press volume Butten per your need.