Works on several different surfaces! Objects that are hollow perform much better than objects that are more dense. Below is a list of materials that it seems to work well with.

• Acrylic
  
• Wood
  
• Plastic
  
• Glass

The bone conductor transducer produces that best quality sound when it's pressed up against a surface. If the bone conductor box is loosely placed on a surface, it will cause the metal plate to vibrate the surface to much and cause clippy audio.