The RPS-ERP-II-EURO needs a IEC320 C14 adapter which fits into the IEC320 C13 sockets on the back of the 220V NON-US Version of the remote power switch.
You can purchase the US and some of the foreign versions at www.sfcables.com or from a local in country source. Here is a link to one of the cables for the US. http://www.sfcable.com/P7PA-01.html
Note the US 120V versions of the RPS-ERP-2 have standard US sockets.
Product Link RPS-ERP-II Remote Power Switch: