I bought a few of these because they were a great price and I'm trying to potty train my son.  Perfect for middle of the night bed wetting, just take off the wet sheet and wipe it down with a wet cloth, spray some lysol, put on a new sheet and you're good to go.  No need to worry about ruining your mattress!!  The only things I don't like are that it has a plastic sound when turning over on it and it is pretty thin so you need to be careful when putting it on so it doesn't get holes in it.