Clever puzzle, moderately challenging, always fun. Hanayama rates this as a level 2 on a scale of 1 to 6 (where 6 is those most difficult.) Your experience may differ substantially. Ratings are subjective. Number on the packaging indicates level of challenge in relation to the other puzzles in this series.
BOX is one of the newer releases from Hanayama Puzzles. New October, 2012. Great for fidgety hands. Perfect to leave on your desk or coffee table as a conversation starter. Great puzzle for ages 10 to 105 years. A few bright 7 to 9 year olds (who will not force) may also enjoy this challenge.
There are 45 plus different cast metal brainteasers in the Hanayama series. Hanayama is the Japanese manufacturer of these puzzles.