This is a utility item that you will find useful in tricks with liquid.
A classic use is to pour a glass of water into a styrofoam cup. Using a knitting needle or kitchen knife (not included) you spear the cup through the middle and spin the cup around proving the water has vanished.
Comes with instructions and performance ideas. Remember this is not a trick in itself, but a utility prop that can be used in other tricks or routines. You'll get several performances out of a single bottle.