The IEC Proof Plane is a classic tool for use in teaching electrostatics. It is used for accepting and transporting an electrostatic charge from one place to another. It has either a flat disc EM2520-001 or a spherical EM2521-001 format. It consists of a smooth disc or a sphere, about 20mm diameter, mounted on a very insulating handle about 150mm long. Read the PDF file for more information.