Pros: keeps water heated...so they say
Cons: spills constantly
I purchased this because MPC said it was very good from all the ones they tried. Well, I don't know if it will heat water as stated because it's summer. But I can tell you that you have to carry it upside down until you get to the coop, then quickly flip it over outside the coop, then very carefully, very slowly place it in the coop. The problem is the tray fills completely to the top and spills over with any tiny movement. I hate it. When winter comes I'm buying a galvanized water-er and putting a heating cookie tin under it. I found DIY instructions on "The ChickenChick" blog I read.