This is a hefty aluminum puzzle with a very special lock. No force, no banging, no centrifugal moves. The object is to retrieve several items inside the puzzle, undo the lock, and then return everything to its original state. Very interesting mechanical design.
The reason why this puzzle was titled "Pleasure and Pain" was because, in its original configuration, it was possible to get completely stuck. Solution included. Emergency key to get unstuck (which I purchased from Strijbos when I got stuck) also included.
It's also called the "Butterfly Lock Box" because of the patterns formed during manufacture on the back of the puzzle