PIRA Code(s): 3D32.15 Set up time:No setup required. Operation: First, slide blow into the mouthpiece located at the top of the whistle. Next, move the piston to create different frequencies. If you have trouble moving the piston and blowing into the whistle simultaneously, have another person work the piston. Physics and Science Concepts: Waves, Oscillations, Frequency, Pitch Safety: Do not blow too hard or for extended periods of time as this may cause dizziness or headaches. Clean the mouthpiece in between use.