This is my latest useful 3D print, I printed a whistle. Here is a picture of how it looks.

It is amazingly loud, works really well and was a very easy print.

The print settings are simple, I used 50% infill. Here is the link to the code:

https://www.thingiverse.com/thing:2933021

See more details in the following video. Note that the volume of the whistle kind of messed up the audio in the video: