Otium 4,000mAh Bluetooth Speakers Max Bass 20W Portable Wireless Speaker with Microphone Bluetooth 4.0 Metal Made Stereo Subwoofers Up to 10h MP3 Music Player with 3.5mm Audio and 0.6ft Cable

Advanced Bluetooth 4.0 -- Fast paired, quick response within 33ft,, fluent signal trasmission wirelessly for music playing, phone pick-up. You can connects to Echo Dot through Bluetooth or 3.5 mm stereo cable to play music.   20W Strong Bass -- Built with dual 10W 45mm 4ohm drivers and central bass radiator, 80db max volume, quality compares favorable with home audio system.   Up to 10h Music Playing -- High capacity 4,000mAh battery allows 7-10 hours music playing after 3-4 hours charging, long lasting enough to entertain you for party, camping, boating, hiking and more outdoor activities.   Superior Casing Design -- After reviewing tens of wireless speakers, we've spent half an year working out this mould, which is far more outstanding beyond most others.   18-Month Warranty -- Otium offers 30-day free money back, 18-month warranty and lifetime dedicated support to assure you long term enjoyment.   Quality Sound Materials, perfect quality enjoy! 18-core aluminum alloy speaker+Composite membrane +Drive permanent magnet+TPE sound vibrating film, meticulous and crafted. Design philosophy is basic of the pursuit of perfect sound quality.   Balanced Frequency Balanced frequency 160Hz-20kHz, response with enhanced. Passive bass diaphragm, offering perfect sound performance.