Raised bubble-up cat fountains give your cats an elevated drinking area above the main fountain bowl. This makes it easy for longhair cats to drink without getting their fur wet. And that makes it easier for them to stay clean and keep you and your home clean. Almost all of our raised bubble-up fountains come with a ceramic insert which when in place creates a tranquil pool of water and eliminates any water sounds. Without it the water will make a bubble-up which can be quite attractive to cats and can also generate a tiny bit of water sounds but can also be silent if a quiet cat fountain is what you want.