Shepherd's whistle

Update (Dec 19, 2014): Two new versions are available. They allow you to thread some twine through them!
http://www.thingiverse.com/thing:601653
http://www.thingiverse.com/thing:601656

A whistle commonly used by Shepherd's for giving commands to dogs. These things require a bit of practice to use, but can be very loud and fun once you get the hang of them.

Check instructions for further information on how to play it.

**Only use the whistle if you're using non-toxic materials
*Update June 26, 2014: Louder and easier to play whistle has been uploaded
I've also added a drawing to better explain how to use the whistle.
*Update September 18, 2014: Uploaded gcode of improved whistle because current version of Repetier and Slic3r aren't working as well for it.