The Piezothing is a small feedback instrument containing a piezo microphone, a FET preamp, an amplifier and a small high quality transducer.
The mechanical feedback through a surface it is placed on produces both a physical vibration in the the surface as well as an electronic signal available at the headphone/line output.
The unit is powered by a built in battery and charges via mini USB-connector. It consumes very little power and can be run intermittently for weeks on a charge or, when used as an installation, for around 6-8 hours continuously.
The size of the unit is 54 x 85 x 11mm and it weighs 70 grams.