This extra-large needle electroscope is ideal for classroom demonstrations of electrostatic principles. A light-weight metal vane is used as a pointer in the electroscope. This light-weight metal blade deflects when the electroscope plate is charged. A transparent scale is provided to measure the angle of the deflection. The front glass window slides up to allow insertion of ionizing material in the chamber.Assembled the electroscope measures: 250mm x 200mm x 120mm.Associated Products include:Electrostatic Rods DustersZinc Plate