I love doing this effect. It's very easy to do but is very powerful at the same time. I usually do two phases from Justin Miller's divorce routine, say that I prefer black rings over silver rings, and end with the ring changing to black. I like the idea of doing a small routine with the ring bcause it kinda creates the illusion for the spectator that they're seeing the entire ring.

When it comes to angles, this can't be done completely surrounded. It's an effect for 1-3 people. But just because a trick is angle sensitive doesn't mean it's a bad trick, so don't completely dismiss this just because of angles. For what the effect is meant for, it's excellent.

This ring does end completely examinable, I disagree with the review above/below me. When you compare the regular ring to the gimmicked ring side by side, it is slightly different, the regular ring isn't as shiny as the gimmicked ring. So, they're not 100% identical. But realize this, that difference is only noticeable when you compare them side by side. Your spectators are never going to get the chance to compare them side by side, which is the only way to notice the difference. This basically means that you shouldn't have any problems handing this ring out for examination. I have handed the ring out for examination several times after purchasing this, and not a single person has noticed the difference.
Also, know that you don't have to hand the ring out for examination every time you do this. Similar to the invisible deck, sometimes when you do this, people may be so impressed that they don't ask to examine the ring.

Overall, this effect is powerful, easy to do, and ends completely clean. I highly recommend it.

For a one-on-one effect, this is okay. You have angle issues that prevent this from working on too large of a crowd. Also, the description says it includes a ring you can hand out for examination. That is true...except for the fact that the examinable ring is noticeably different from the one you do the effect with. The effect ring has a constant shine over it, while the examinable one has a very dull design in the middle that doesn't shine at all and won't. This isn't a subtle difference here at all; even a casual glance will tell the spectator you aren't giving them the same ring. That means you have an effect where you "show" a black ring and change it to silver (or vice versa), and then you have to pocket the ring afterward and move on. Yes, crowd control can manage that, but the description says you can hand something out and that's misleading.