The Cast Ring is made up of four pieces; two gold bands and two silver bands. The Ring doesn't fully come apart into it's four separate pieces, the pieces still remain tangled together once they have been disassembled.
I was actually quite surprised when I held the Ring for the first time because I wasn't expecting it to be as large and heavy as it is. For some reason I was expecting it to be slightly larger than a normal finger ring, but it is in fact quite a bit larger than that! But because it's large it makes it relatively easy to manipulate, and I imagine it wouldn't be quite as fun if it were too much smaller.
When I reviewed the Cast Amour I said that I wasn't a big fan of the gold and silver design, but in the case of the Cast Ring I actually think it works really well. Probably because I'm so used to seeing jewellery in gold and silver that it just looks right.
This puzzle isn't particularly difficult but it is quite enjoyable. It sits well once it is in the solved position, which also makes it good as a display piece. I think it only took me about 5 or so minutes to solve it, which I don't think really matches up with Hanayama's difficulty rating of level 4 out of 6, but I can see how you could easily get yourself tangled up with it and end up going round in circles. But it is a really good puzzle and definitely worth the reasonable price.
You can buy the Cast Ring (along with all of the other Cast series) from Puzzle Master.