Rheostat - Standard, Resistance 16 Ohms, Max. Current 4 A Rheostat is wound with heavily oxidized constantan (Copper-Nickel Alloy) wire on a vitreous enameled steel tube. There is a heavy duty sliding contact made of phosphor bronze and nickel plated for corrosion resistance. There are 2;4 mm terminal posts which are fitted to facilitate external connection conventional 4 mm plug This Rheostat is wound with heavily oxidized constantan (Copper-Nickel Alloy) wire on a vitreous enameled steel tube. The tube is supported on die cast ends. There is a heavy duty sliding contact made of phosphor bronze and nickel plated for corrosion resistance. There are 2;4 mm terminal posts which are fitted to facilitate external connection conventional 4 mm plug