Each Fire Pit Art® creation is fabricated from one quarter inch thick mild carbon steel and has an applied iron oxide patina on the outside. Solid. Sturdy. Made to last forever. There is no required maintenance even in cold, harsh environments and can be left outside year around. All designs are easily adapted to propane or natural gas equipment. Each fire pit is hand crafted and individually numbered on a small brass plaque attached to the base ring. Pick out your own work of art!