My sister gave me a ring that is beautiful and I believe it is celtic. Is there any meanings or background behind them? Thanks for your help.

I'm getting married soon and I wanted to get a celtic shield ring for my fiance. However I can't decide if I should get one with or without the "rims". To me it would seem uncomfortable to have the rims. So I was wondering if any of you guys had any input ot experience with this. The ring can be seen at uniquecelticweddingrings.com . Thanks!