Retrofit kits are bottle filler kits made to fit on top of an existing fountain. It allows to turn fountains into bottle filling stations without having to fully replace them. Each kit has been made to fit a specific fountain design.
Retrofit water bottle fillers do not come with any refrigeration system but if a refrigerated fountain is being retrofitted, the chilled water will carry over to the bottle filler. Same goes for filtration, although all retrofits are available without and with filter kits for existing fountains that would be lacking one.