This water bowl lets my dog have a drink whenever she wants, but otherwise keeps the water in the bowl.
It really sucks when you pull over after an hour or two of driving to find the floorboards soaked and your dog has lost all her water. These non-slip, no-spill bowls solve that.
Another benefit of this bowl is that my Cavalier King Charles, does not dunk her ears in the bowl while drinking. The tapered lip that snaps on atop the bowl really keeps water in, and reduced the size of the open to just one the doggies face fits in. The slobber control portion of the bowl doesn't really keep my sloppy Golden Retriever from splashing water in my kitchen, but it helps.