I filed down a Fox Forty Classic. I also removed the little tower on the end that holds the lanyard hole. Turns out that the little tower was hollow so I now have a 0.25" hole in the end of the whistle. It would be easy for me to glue a little piece of plastic over the hole to cover it up so I don't have to remember to cover it up when I need to use it (or when some unknowing companion needs to use it).<br><br>Low power tests (I live in an apartment building) indicate that the whistle works as well or better with the hole open. Does anyone else have experiences with this? Is it better to cover the hole?<br><br>PS: I don't think it is healthy for humans to live in a place where they can't test a whistle (or a tent).

I did the same and filled the hole with the melted ends of a short paracord loop. Goes in the tin really flat and compact. You can also grind the blow on part much shorter too!

I did the same too! After comparing it to an unaltered one and finding little difference, I just left the hole. <br><br>Although, my old ear's aren't what they used to be, especially now after the whistle testing-- perhaps I shouldn't have done it inside the cab of my truck?