They are coated with a durable polyurethane finish to resist moisture. The metal top channel is aluminum to create a dynamic contrast to the tile. The reservoir is covered with your choice of polished river rocks or seashells. All of our fountains recirculate, so they do not require any kind of water connection. All you do is place about a gallon of water in the reservoir. The quiet, powerful adjustable-flow water pump lifts the water to the top channel, where it falls over the slate into the reservoir below. This cycle continues as long as the fountain has enough water, creating the soothing sounds of a rocky stream. And the warm interior lighting provides a dramatic visual display that will make any room truly special.