Yes, with the companion app, two Sugr Cubes can be paired to a stereo set. It rocks!
There is 4GB built-in memory, it is fixed just like an iPhone. There is no external memory card slot on Sugr Cube.
Sugr Cube plays at least 7 hours at max volume after a fully charged. Please be noted that playback time is music type dependent. If you enjoy soft music with medium volume, it lasts at least 20 hours.
Yes, it works when charging.
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