Nozzle itself is made in one single piece from 303 stainless steel which is generally used in food industry. Inside is without cavities and polished, this makes nozzle extremely easy to clean.
As usual my design is GNU GPL v3. You can download the drawing here (I suck at drawing, I'm having pro drawing made right now!). If you make them, just don't be a d*ck and don't pretend they are done by me ;-)