Revision Card Ring

I have designed this revision card ring, so that people mostly students who use revision cards or record cards can keep there cards together easily and neatly, with the help of this ring. I have not printed this out as I have not got the time to do so, but will do. please let me know in the comments on what I should improve on. This has been designed to hold a 100 cards and the hole diameter is 3.5 mm, which gives you enough room to flip a card over. Please give me credits if you are remixing th