The electric recirculating pump allows you to enjoy this fountain during the day or when you run it at night enjoy the ambiance of the fountain's LED lighting. About the Polystone durable material. Polystone is more durable and heavy than resin or fiberglass fountains but still much lighter than the concrete or stone fountains. It has a porcelain like feel to the touch and an incredible ability to capture the most minute detail. Polystone is a compound made up largely of polyurethane resin mixed with powdered stone additives that give it added weight and the porcelain or "stone-like" feel that resulted in the materials name itself. Polystone is durable and highly effective at maintaining a sharp paint finish. Polystone is a cold-cast material in which no heat is used in the manufacturing process resulting in much greater variations of paint finish.