It is made from the protective case for a 12 cc hypodermic syringe, which can be purchased from a pet store or veterinary supply store. I use the syringes as tools for extruding silicone rubber in making silicone rubber sculptures. This is a good way to recycle the protective cases.
The needle cover (pink) is sanded down to make the mouthpiece. The reed is cut from a piece of scrap plastic that I recovered from a junked flat screen monitor. Electrical tape holds it all together.
To protect it in my pocket, I made a carrying case out of PVC pipe.
To hear how the hypotooter sounds, listen to the .mp3 audio file in the last step.