Solid Steel with welded Steel Balls to cap the metal. Sizes: This is our small iron topiary. If you have a short vine that needs support this wire frame could support it. Measures 22" tall and the balls are 15.5" apart. The top ring is 15" diameter and the bottom ring is 10.5" in diameter. This is our medium iron topiary. It can be used as a tomato cage. A frame to hold drooping vines or an ornamental accent in your garden. Measures 30" tall x 17" diameter. The middle ring is 16" diameter and the bottom ring is 11.5" diameter. From the ring to the bottom of the topiary is 6.5" This is our large iron topiary. Set it in your garden to hold up your tomatoes or a drooping vine to make it stand up. Measures 36" tall 31" after staking with the balls 17" apart. The top ring is 17.5" diameter and the bottom ring is 13" diameter. When ordering multiple sizes they will nest together.