Epsilon Electronic Equipment & Components Pvt. Ltd. Supplies Electric Lamp Filament Switching Unit. Epsilon Electronic Equipment & Components Pvt. Ltd. Manufactures signal & telecom items for the Indian railways. Electric Lamp Filament Switching Unit is for color light signals. Electric Lamp Filament Switching Unit can be used for 12V, 24W and 12V, 33W. Triple pole lamps used in color light signals. It is possible to fix this unit in both CLS unit as well as in location box provided near the signal post.