SmartBB Wireless Bluetooth 4.1 Speaker Stereo Amplifier with Micro SD Card Slot 32GB TF Card 3.5MM USB HandFree Multi-functional Drum style Bluetooth 4.1 speaker with TF slot/line in,aluminium alloy body Built-in microphone, support hands free when answering calls Simple and sophisticated design With TF card slot, reads MP3 format audio file from TF card Speaker selector and speaker terminals for two systems Bluetooth for connectivity to streaming music services