Graphite-pencil, withg cable

For marking field lines; glycerine is placed in a cuvette as a conductive liquid, the graphite pencil can then be used to record the field lines on a piece of paper lying on the floor;
Graphite pencil in metal housing, with cable and plug pin
Dimensions: D=8mm, L=135 mm
Cable length: 35 cm
Mass: approx. 24 g