Merry Christmas, or Congratulations, or something similar. There are fine ridges along the tape, and your thumbnail acts like a phonograph needle. If you attach the end of the tape to a balloon or a paper cup, this will act as an amplifier, and you can demonstrate the effect to other people. A two metre tube made of very light plastic. The challenge - to inflate the tube with a single breath.
Trouble is - the volume of the tube is much greater than the capacity of the human lungs.
A least a dozen different items in each pack. Lots of entertainment and fun. Grand Illusions Shop.