  Core of SoundBug speaker. 
This is the heart (not easy to get to!) of a SoundBug brand magnetostrictive alloy speaker.  The rod you see sticking out of the copper coil is made of Terfenol alloy, which changes its length when exposed to a magnetic field. 
Source: Max Whitby of RGB 
Contributor: Max Whitby of RGB 
Acquired: 17 April, 2009 
Text Updated: 17 April, 2009 
Price: Donated 
Size: 0.5" 
Purity: <50%
 |  
  |  
 |  
  |