Loud Whistle with ball - 128 db

Check ball position. It's should be at the bottom.
No need support and fill.
Wall thickness can be 0.8 mm.
0.4 mm nozzle recommended.
128 db measured

After print;
The ball inside should be carefully broken with the help of a thin metal and released.

Design by lu_print on MakerWorld (license: CC0).