Just got back from a trip to Europe. I took this along and it worked fantastic! I used one adaptor to charge up to four devices at one time. Every thing we plugged in was rated for 110v-240v so I didn't need a convertor to go with it. I wrote to Monster customer service before ordering and they told me it would be fine to use without a converter and it was absolutely true. Used it in both France and England, no issues what so ever. I solved the problemm of most adaptors not accepting a 3 prong U.S. plug by buying a jump adaptor to plug into my international adaptor at the hardware store for less than $1. Ask the guy in the electrical department, he will point you to what you want. Good luck and don't worry, it works!