Sam writes –

The chinese finger trap is a novelty toy which traps the index fingers of an unsuspecting victim inside a small cylinder.
The harder the victim tries to escape, the more the finger trap tightens. As such, the chinese finger trap has become a metaphor for struggle and offers a simple life lesson: things are sometimes more easily accomplished if one does not try too hard. I have been looking everywhere online for instructions on how to make these, but could not find anything. The finger trap I describe here has not been reverse-engineered: I have no idea how the toy is normally made (though I suspect it probably is very similar).

How to make a chinese finger trap – Link.