I bought a bunch of these when I moved to the UK to run all my US stuff on. I had one so big it ran my washer machine! I'm not sure about Greece, but Germany and Austria are the standard 2-pronged round plugs. Some of the power converters come with this already on it, so you may not need the adapter in addition to the converter. Most of the standard stuff will run at 50 hz, so I wouldn't worry about that. If you have time, I would definitely buy online. I have a few of the "travel" type that have a switch to go from 50 watts max to 1500 watts max. This is sort of a one-size fits all for travel as you can run an electric razor, mp3, etc. on the low watt setting and an iron or blow dryer on the 1500 watt setting. The high watt setting is only meant for short term use.