Artist Rick Wittrig creates unique and customized fire pits from one quarter inch ( 6.35 mm) thick steel. This is by far the heaviest gauge metal used in any fire pit available today. The sturdy construction assures you of having this functional art for many years to come. They have an iron oxide patina on the outside which will darken a little with time then become permanent. The inside is coated with a high temperature resistant paint and has a rain drain in the bottom. The high quality and craftsmanship help assure that this will be the last fire pit you will ever own.