Borrow your spectator's ring. In one smooth motion, you put the ring in your pocket and instantly pull out a sealed brass box. Let your spectator twist the top from the container- and here's the first amazing part. The top has so many grooves in it that it will take at least 15 seconds for him to screw the top off! When he opens the container- the ring is inside the box!
But HOW did the ring get into the box, your spectator will wonder?? He'll know you could not have put it into the container and screwed the top back on- remember, you instantly took the container from your pocket. What a mystery- which is why this one is called the Brass Mystery Box!
But wait- that's not all! Use this box to produce a vanished coin, or a secret message, or the ripped corner of a vanished card, or anything your imagination can dream up!