Help - please explain

Ok cos I am a bit nappy challenged I need some help!

I have been looking at snazzipants cos they are really cute and am a bit confused do you put the nappy on then put a cover over top of it???

And do you have to change the cover everytime you change the nappy or will it last a few goes?

And can some one tell me about sizes and roughly how long each size would last.

Thanks

Edited by floss

i use snazzi fitteds, and i only generally use one cover a day now that we are past the explosion stage. Jordis is now 6 months old and is still got plenty of room in her size 1 snazzis. i dont expect i will need to look at sizing up for a good 6 months yet at least - but she is pretty little though!
and yes it goes nappy and then cover