An excellent unit that is very sensitive in detecting electrostatic charge but is also robust and not easily damaged. A very thin metal vane is carefully pivoted and balanced in a small frame inside a container with glass sides. When a charge is deposited on the electrode disc at the top of the electroscope, the vane pivots and deflects. A 4mm socket is provided for earthing the metal casing. One glass side panel is removable for access or for inserting radio active sources for other experiments. See the 'PA' section for spare parts.