This adapter will let you plug into a US 2-prong power adapter in the following locations:
Germany, Austria, Italy, the Netherlands, Belgium, France, Spain, Portugal, Denmark, Norway, Sweden, Finland, Greece, Turkey, Israel, Poland, the Czech Republic, Slovakia, Hungary, Rumania, Bulgaria, and Russia. Also used in the Middle East, most of Africa, South American and many developing nations.
Compatible with all the power adapters Adafruit carries as all are 110-240V compatible!
Note that this does not contain a transformer, its not going to transform 120VAC to 220VAC, its only a mechanical adapter so its only for use with devices that are OK with 220VAC! These are good for up to 3 Amps continuous current (thats 660W!), for anything more you'll want a solid-fibreglas construction module