Vtin Royaler Stereo 20W Speaker Dual 10W Drivers, Aluminum Housing, Passive Radiator, Strong Bass for iPhone and More 20W Powerful Drivers. Enjoy the high stereo sound with powerful volume powered by dual 10 watt drivers. The passive subwoofer lets you enjoy the rich bass. Deep Bass. The passive subwoofer and radiator improve the quality of bass. Just stream your favorite music with VTIN 20W speaker. 8 Hours Playing Time. With a premium rechargeable 5000mAh polymer-Li-ion battery, it provides you 8 hours playing time at the volume of 50%. Al Alloy Housing. Featured with high-strength aluminum alloy case and high precision CNC polished tech, the speaker is durable and sturdy. Anodic oxidation process makes it stylish. Bluetooth V4.0. Supports connect your Bluetooth-enabled devices at the range of 33feet. The auxiliary port easily helps you connect your other devices without Bluetooth function.