?Vol? Speaker Is It?s Own Volume Knob

Hironao Tsuboi’s minimalist speaker has an equally minimal name: Vol. The speakers are simple aluminum cylinders, and their volume is adjusted by turning the edge of the speaker itself. Turning a little bit further will click this switch into the “off” position.
Vol is powered by a rechargeable lithium battery, has a jack socket for plugging [...]

Source: http://www.wired.com/gadgetlab/2011/07/vol-speaker-is-its-own-volume-knob/

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