Econobum, this diaper grabbed my attention first with the price and then with the idea of reusing the shell. It comes with a prefold that you place in the outer shell and then snap on. While this is very economical and will work. The prefold tends to move so I will not use it at night, and it's pretty bulky. My daughter says, "Not pretty" and "Not soft". I like that it is one size and can grow with the child.
Above is the prefold and the outer shell.
Above is how the prefold in to be laid inside of the shell.
Above is my 2 yr 4 month old daughter modeling the diapers. She is 28 lbs and very well in the average for her size. Just to give you an idea of how long you could use these one size diapers. We are keeping his one, but not ordering anymore.