A pretty old puzzle designed by Doug Haigh and crafted by Bits&Pieces which goal is to get the diamond and free the metal ring.
The diamond can be obtained by removing the metal top above the plexi part, but this is not the intended way to do that.
This is a pretty small puzzle but with a nice sequence of steps. I like when many things are hidden in small puzzles. That means you don't need to have super big puzzles in order to have a sequencial discovery puzzle! :-)
While not extremmely difficult, it's still a nice challenge, especially for beginners. But even a seasoned puzzler will find it nice and would need it in its collection.
I am wondering if this puzzle has ever been made by a famous craftman or only by Bits&Pieces. Any clue?