[bossref]

Any time you change whistles, it will take time
to adjust to the difference in tone or how hard you need to blow, or if it's too loud or not loud enough.

If you work games in gyms that don't have too much fan noise, you can use the Fox-Pearl.

The tone is lower than the Fox-40.
The wholesale cost is slightly less than Fox-40.
They are made for survival, hunting, boating ,etc
but work very well (once you get used to their tone)
in gyms where the crowd noise level is low.