HDX Metal Shelving Anti-tip hook

I purchased a 5-Tier Steel Wire Shelving Unit in Chrome (36 in. W x 72 in. H x 16 in. D).  When I set it up in the craft room(on carpet) I realized it was a tip hazard.  

I designed this originally to help prevent this from happening. I can't guarantee that these will hold in every situation but I'm sure they can handle the random bumps that occur.  Obviously, proper loading of the shelves is helpful as well. 

Print and use at your own risk. I used 20-30% infill on mine. There are 2 sizes because later I received a 48X72X18 inch shelf and it has a larger diameter vertical bar.