Vandesail RF BS-Black Bluetooth Speaker STRONG ALUMINUM ALLOY MATERIAL: Made of high quality aluminum alloy, guarantee a long using life. Pure toning by anodized housing shows premium metallic quality, very noble and fashion. This wireless speaker is compact and portable, convenience to carry on. BOOMING BASS, POWERFUL TREBLE : VANDESAIL Bluetooth speakers feature 2+2 acoustic structure, symmetric 40mm audible unit and passive side for enhancing bass performance. 1456 sound holes finely carved by CNC, present full stereo music vibration. BLUETOOTH 4.0, WIRELESS RESTRAIN: The latest Bluetooth 4.0 technology, instantly and steadily connect to your smart phone or laptop from up to 49 feet away. It remembers the last eight devices used, so reconnecting is automatic. PORTABLE AUDIO, MULTIFUNCTIONS: A new double track stereo decoding, support TF card, U disk, plug and play function of the radio. Built-in microphone for hands-free phone calls, great noise reduction quality let your calling more smoothly. PORTABLE AUDIO, MULTIFUNCTIONS: A new double track stereo decoding, support TF card, U disk, plug and play function of the radio. Built-in microphone for hands-free phone calls, great noise reduction quality let your calling more smoothly.