Product review (4 stars): The ones I got fit and are functioning after fixing with hot glue as needed..
It seemed that the newer reviews had  more positive opinions so  I rolled the dice on whether I would get the good ones or get the bad ones. What I received was two of them being functional but brittle and the other two were broke apart in a couple places. For whatever reason the glue that holds them together is failing.
Using a hot glue gun I glued the broken ones back together, then I ran a bead of glue across the op and the bottom and then on both sides. Now the humidifier is adding five  gallons of water a day into the air without incident.