Some time ago there was a bit of (created) 'hype' regarding the Dael O Ring
in The Netherlands.
Fact is that it is since long a puzzle that can be bought in general toy shops (and not only in specialized stores).
In my youth wooden, metal and plastic puzzles were more general available in toy shops, as shown on Katsmom's pages
Any experience with a Dael O Ring? Is it basically a simple copy of the Revomaze