I found the following relay module from Adafruit on Google: Controllable Four Outlet Power Relay Module version 2 [(Power Switch Tail Alternative)] : ID 2935 : $39.95 : Adafruit Industries, Unique & fun DIY electronics and kits
But because I live in Germany I'd like to have a similar module which is from Europe, preferably with a German plug.
Does anyone know a similar product?
Thank you for your help.
Hi,
Have you emailed Adafruit about the plug, it is a lead with IEC plug for the power unit, the mains should be supplied with your countries plug.
Tom..... 
it is a lead with IEC plug for the power unit, the mains should be supplied with your countries plug.
Correct, but the female connectors on the power unit are not EU or German style. This is the problem to be addressed.
Following a picture of a Schuko connector which comes with ground connectors. For non-grounded devices the socket is a bit smaller.
@embie27:
I found a youtube video with a DIY solution (maybe a DIY kit) which comes with non-grounded sockets which seem to fit for German plugs. But: You are dealing with mains !!! So make sure that you know what you do or ask somebody with the right experience/education to help you make this thing safe.