Greenhouse Garden Hoop Mounts

I have several 2' tall raised beds in the yard and acquired a couple of sets of the garden hoops sets from an online store. These mounts attach to the top of my raised beds and add needed stability and additional height to the setup.

I've included 3 sizes, depending on the diameter of the poles used. I'm using the 7mm mounts even though my caliper measured the poles I'm using at 5.7mm. Probably designer error.