This pack of five spare O-ring belts is designed for use with Eisco-branded Van de Graaff generators (model EDUVDG). The O-rings are essential replacement parts that maintain the charge-generating function of the electrostatic generator. Van de Graaff generators use the belt to accumulate electric charge on a hollow metal globe mounted on an insulated column, producing very high voltage direct current (DC) electricity at low current levels. Keeping spare belts on hand ensures the generator remains operational for science demonstrations.