The Periscope is an excellent and unusual puzzle. It has a ring, a slot, several posts and even a piece of cord, albeit a short loop. It is by Toys International of Montreal, Canada and Made in China. Thoughit is listed here as Family Games IQ Collection Brain Baffler Periscope. It derives its name from resembling a submarine periscope as the cylindrical piece can be raised, turned and lowered through the slot. It is very well made of high quality hard wood with a good finish, a firm steel ring. and a heavy cord loop. PuzzleMaster rates it as a Difficulty of 8, or Demanding, on a scale of 5 to 10. Personally, I don’t think it is that difficult, more like 6. It’s fairly large, 7 2/5 X 5 1/4 X 2 1/2 inches.
However; I made it hard for myself when first trying to remove the metal ring. The ring had a paper wrap around it, for whatever reason I don’t know. I found it impossibly hard, until I removed the paper wrapping and found there was a gap in the ring, which was very helpful in solving.
This would be a good choice for any puzzle lover (Metagrobologist) whether a novice or expert.
You can purchase this puzzle and get the solution at Puzzle Master.