These cards are great, I love that they are on a metal ring so that you can swap about and they are a nice convenient size - I carry them about in my handbag and pull them out over a coffee.
I have one criticism though. The CD is all over the place. I put it into my laptop to listen while flipping through the cards (in order!) and the CD goes from card 1 to card 10, then 100, 101,102 etc. So I can't just sit at my laptop listening flipping through the cards. That's a little disappointing. I will try the CD in my car to see if it does the same!