Ball and Tube (Locking) by Johnson Precision Magic

This old pocket trick becomes a miracle when performed with our
precision made apparatus. EFFECT: A steel ball is set on top of a small
brass tube. The ball is obviously larger than the tube. Slowly the ball
sinks down into the tube; then just as mysteriously it rises back to the
top. Instantly both the ball and the tube are handed out for
examination. Nothing is palmed or taken away. This is a guaranteed
collector’s item that you will use.

Easy to follow routine included.