Sbosent Bluetooth Portable Speaker, Wireless Bluetooth Speakers V51Usb Card, Micro Sd Card And Fm Radio, Wireless Speakers With Bluetooth-BlackProduct information- Name: Portable Bluetooth Speakers- Working distance: 10M- Wireless: V51- SNR: =90db- Normal volume playing time: 6H- Frequency response: 120HZ-20KHZ- charging time: about 3Hrs- Support H..