Its nothing more than plastic garden fence from the local big home improvement store. I cut off a piece connect the ends with zip ties and pin it to the ground with small sticks being careful to stay clear of the root. I use a small piece for a lid and it seems to deter deer and has gotten a lot of nice seeds to planting stage. I have a few larger ones for plants that are growing in a group. When the berries get red I plant them roll up the cage and put it in the shed till next year.
I know they're easy for a poacher to spot but so far I've been lucky and I don't have a big security problem here.