Wonderoos is a one-sized pocket diaper that is lined with suedecloth instead of fleece. Since I have 2 kids in pocket diapers, I thought I would give them a try. I would definitely say that they have a small fit but since I have small kids, they work out great! The suedecloth works really well at keeping them dry and no poopy leaks out of the legs yet, which I definitely can't say for FB! Overall these are awesome diapers and I hope to get more soon.