i buy the "big" tomato cages, then cut what i don't need out with a bolt cutters....there are three different dia. rings on them, a 12", 14", and 16".....i usually use the top ring, and depending on what height i want my plants, i cut the length of the legs accordingly....then i bend feet on the end of the legs so they don't poke through my smarties, and anchors it into the soil....it is the best method i have found for canopy control, because it is so versitile.....you can bend braches over, and soft tie them down to the ring, or after soft tieing, can shift them left and right laterally on the ring to instantly modify the shape....like when jamming them into a tight grow space, puzzle piece style.....i think i may have some custom ones welded up for my bigger outdo plants.....thanks for asking.....nugs
i posted this at CC for you, along with some pics......diggin' it over there..