This is a clever coordinate motion puzzle box called 2024 "Looney Module" designed in 1974 by James Dalgety. He has generously given me permission to sell my version here. As usual, I include a clear plastic box that fits the puzzle perfectly.
You can read more about James and about this puzzle in a paper he contributed to the 11th Gathering for Gardner in 2014:
https://gathering4gardner.org/g4g11gift/Dalgety_James-Puzzles_Invented-Designed-and_Discovered.pdf
I posted on my blog about this too but you might want to avoid it because it describes the solution.
SPOILER ALERT:
I'm about to explain how the puzzle is solved...
SPOILER ALERT:
You were warned!
I've altered James' original design so that there are no exterior features on which to get a decent grip, even with your fingernails. So that rules out pulling the pieces apart (assuming you knew where to pull). However, since it's a como (coordinate motion) puzzle, spinning it will cause the pieces to slide apart and the puzzle to open. To prevent the pieces from flying everywhere and getting lost or broken, I've added magnets so that it will only open partially when you spin it (unless you spin it really really hard). Then, once partially opened, you can pull the pieces off one by one to take it completely apart.
It is very cool (I think) to be able to casually toss it in the air with a little spin and when it lands back in your hand, voila!, it is open.
Product code: James Dalgety's "Looney 2024 Module"