First of all these say ‘Powder Coated’. The one I received was NOT coated at all. It was cold steel. 
Second, they imply you can mount them in various ways but due to the design of the slotted hooks, they only function in one direction. So, they must be mounted with the vertical slots and cannot be mounted in the horizontal direction. Limits their application. 
Third, the hooks appear to be specialized as I’ve never seen them anywher. Thus, supply sourcing them will be challenging with limited supplier (e.g. manufacturer).

I wouldn’t buy these again.