Was looking for a larger tomato cage to support my 7' tall Sun Gold Tomato plants during windy storms. Was only looking for a 6-footer, but couldn't believe the price on this 9-footer. (Cheaper than buying two arches or four trellises.) Just like all the others, hollow steel(thin wall) tubing. Be wary of defective welded joints(happens on mass production lines) and soft metal screws(stripping out easily). My husband thinks they're aluminum. I'm a welder and can't fabricate this for that price. Not to mention the time. Actual measurements: 74\" wide base diameter, 98.5\" Interior height, 107\" height to spindle peak, 38.75\" wide openings.