This vintage case is marked inside Voltage Valet under a grid map of the World Logo. According to the instructions U.S. Electricity 110/120 Volts products will not work overseas that uses 220/240 Volts and the wall outlets are different. The converters are for 50, 1000, and 1600 watt. The 4 adapter plug set is made for different parts of the World. It was made in Taiwan for Voltage Valet Division Hybrinetics, Inc., Santa Rosa, California 95401. On a search I found the company has been in business over 30 years. I was unable to find this set in their products section. It is used in very good condition.