The Magnaprobe is a great way to demonstrate the 3-D nature of magnetic fields. The probe features a gimbal-mounted Alnico magnet which is free to move in the x, y and z dimensions. As the probe is brought near a magnetic field, the alnico magnet aligns itself with the field. Use it to investigate the magnetic field around various geometries of magnets or the magnetic fields around common electrical devices. Suggested activities are included with each probe. Magnaprobe is 12 cm long.