The original power supply from the Slingcatcher that I purchased in the U.S came with a 100V - 240V power supply
Input 100 - 240V 50/60 mhz
........which should cover your needs in Sweden with nothing more required than a converter plug.
The thing is, when I ordered a replacement power supply through Sling in the U.S, they sent me a 110V version only. Since the solo / pro-hd and catcher have the same power supply, you should be able to get one from Sling Europe that comes with the 220V needed to run the Slingcatcher ( assuming the 220V power supply doesn't come with the used Slingcatcher) . Some used Slingcatcher's have had new power supplies put on them and the chances that it could be 110V only might be a possibility. Just know that you can find a 220V version from sling ( or various other places like ebay) to run the catcher and you should be good to go.
The slingcatcher should work in Sweden without any issues.