Dip Needle.

  Updated version includes scales! Dip needles are very useful for detecting magnetic fields in 3 dimensions, such as large iron deposits under the earth. This one can be used as a dip needle, a regular compass, and as a demo of electromagnetism! Simply rotate the needle against the scale to the desired amount of degrees. In addition, the gimbal is equipped with banana jacks to allow electrification. This deflects the needle proportional to the amount of electricity.