It seems really solid, but the cuff rings are just too small for me to give a proper review. Truth is, I basically have to bruise myself just to fit it in, and it's terrifying. I just imagine having to go to the ER to have it cut off. It took about 5 minutes just to get it on, and I immediately took it back off out of fear.
I've been scouring the internet trying to find a 2.5 - 2.75" version that would fit this device, but no luck. That said, 2" seems to be the standard "large" that comes with other similar products, so if this isn't your first experience, you probably wont have any problems.