Cast Donuts

Donuts is the newest (Nov., 2011) Brain Teaser Puzzle from the Hanayama Company of Japan . 
DONUT puzzle has four of the same shape pieces that are loosely interlocked together to make up the puzzle. Because the pieces fit loosely it would seem that it would be easy to take apart. However, one is soon at a loss, as the puzzle gives little hint of how it might be solved. This puzzle requires patience and perspective.
 
This is an interlocking style puzzle where pieces need to be moved slightly, shifted left or right, then another piece moved slightly and shifted in a series of numerous moves. You may solve it without being certain of all your moves ! Reassembly is equally as challenging. 
 
Like all good puzzles NO FORCE is ever required. Just clever, insightful movements.
 
Small, compact, hand-size, tricky puzzle. Rated as a level 4 difficulty by the manufacturer (on a scale of 1 to 6 where 1 is easier and 6 is most challenging). Puzzle difficulty ratings are subjective. Your experience may differ
 
 Recommended for ages 12 to 105 years. Some very inquisitive 8 to 11 year olds may also enjoy.