Firstly the design is very good, not having to mess with screws or locks is a great bonus. Simply provide a little lube and slide the metal around. I had no issues with the metal that slides into place to prevent it falling off, a little pressure and it pops right out. These are not heavy enough to be weights but do provide a nice satisfying pull so singularly apparently they just let you know they are there making the everyday a little more interesting.
Maybe I will order another one (or two) for him so they can be stacked.
Overall a great little item that can be added along with cages, more convenient than other similar clamps/weights and its great fun to see him walking with it lol!