It took me five versions to come up with this design. It has two chambers at different sizes giving it a fast alternating sound. It has a hole for a key ring and chambers in the middle so it floats. Give it a print and try it out. It's my first upload so go easy on me. Please let me know if you like it.
any but the finer the better. .08-.1 or up to .2
Works fine in PLA or ABS. I haven't tried other kinds of filament but I'm sure it would be fine. you can print it standing up or laying down. it depends on your printer/settings. I like it best laying down flat with a fine .08 print height.