I don't know the names of the designs, but my advice is from my experience.
I prefer lightweight hard plastic to both silicone and metal. Metal seems too heavy to me and its a constant reminder that its on (im not trying to sound sexy if you're into that, but if you're at work and trying to be productive so you can stay employed, its not ideal) Silicone and flexible material has the issue that most of the ones I have found at the lower price point have unclean sharp edges cut, meaning VERY uncomfortable. I have also noticed that even if you lube them up when you put them on, that lube will go away and that silicone will GRIP your skin, so I could see some serious potential for rubbing you raw. I have cages with all three materials, but silicone and metal are the ones she would change me into if she wanted to see me in a certain color or style, then I would go back to plastic for long term.
Also, I prefer less parts. my favorite cage had a ring behind the balls, a cage that covered the shaft, and then a lock that went longways across the two pieces, NOT the padlock that you normally see. There is less room for the parts to wiggle and come apart, meaning that the potential for pinch is next to zero. Also the sound of the jingling lock is gone. I don't mind the padlock kind, but you HAVE to wear tight fitting underwear/panties to offset the noise and the shifting of all the parts. in the pics, the clear one is my favorite, the kind im describing, and the pink one is the traditional padlock style.
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