THIS VIDEO DEMO IS FROM THE MANUFACTURER:
Take an ordinary wooden toothpick, and poke it all the way through an ordinary cardboard matchbox. Not very impressive? Remove the toothpick and open the matchbox- the box is entirely filled by a solid brass block! How did the toothpick pass through THAT??!!
And this one is SO EASY to do! If you can hold a matchbox in your hand, you can do the trick!
The brass block in this version of the trick is SMOOTH as seen in the demo video. The ordinary matchbox you'll get with this trick can be replaced anytime with a new paper matchbox, available at most supermarkets.
Instead of pushing the toothpick through the matchbox, you can use a needle and thread. Pass the needle and half of the thread through the box, then stop and show that the thread is indeed going right through the box.