Pebbles and small stones & pond-less kit not included. Strong & lightweight concrete bubbler rock. Glass fiber reinforced concrete. Molded from natural stone. Stones with crevasses creates splashing water on the surface. Complete your peaceful garden appearance with this Mesa collection bubbler rock. Molded from natural stone, it has a natural finish and is made from reinforced concrete for all-weather performance. Flowing water creates a serene, idyllic environment anywhere outdoors.