Geophone or Xeofon from Tremor Labs is a device that generates electrical signals proportional to the velocity of the particles in a sound wave. They are mainly used to measure sound waves propagating through the earth or vibrations of different materials.
With this geophone has been designed for experimental sound practice and low frequency recording.
Comes with neodymium magnet, suction cup, ground spike.
Handmade in Spain in collaboration with Tremor Labs (Alvaro gallego) and Mutan Monkey Instruments.

Directivity: omnidirectional
Sensitivity (V/m/s): 80-15% / +5%
Damping: 0,185 
Harmonic distortion(%) : 0,7
Frequency response: 10 – 1000+ Hz
Cable: 1.5 m, 
Output: XLR-3M balanced,  Neutrik connector