Lightweight metal. Don't burn huge fires or the screen will burn off. This 40 inch model does fit our ring of stones. Inner half is about 38 inches. Our city requires a fire pit screen so now we're legal. The photo shows one handle on top. It's wrong. Both handles should be at the bottom when closed. Assembly was easy. If the holes don't line up when you overlap sections, just switch positions of the panels and they will. It works just fine.