Do you have a old industrial shade or light fitting with a large screw fitting that does not fit new bulbs? then its a original E40 fitting. This converter is a cheap fix to the problem of re wiring old lamps. Simply screw in with a new bulb.
Will work with all voltages from 110 to 240
E40 = OLD INDUSTRIAL SCREW FITTINGS
E27 = NEW STANDARD SCREW FITTINGS