This Bluetooth Speaker, by its design concept, is a retro version of a classic rotary knob-on sound player that encourages intuitional user interactions, such as spinning to adjust volume, long pressing to turn on / off, short pressing to pause / resume. In pursuit of styling simplicity, the metal knob on top, with a loudspeaker encircled, highlights its interactive function. Enveloping a 1,200 mAh battery with seven hours life, the chamber still provides sufficient cavity space for good acoustic performances. Both versions, black or white, blend in with most working and living environments and are suitable for both carrying around and desktop placement.