As a returning swimmer, I found my breathing was off. The Tempo Trainer took me from a difficult 75 yard max before stopping to mile workous in one try. This is my second Tempo Trainer. The old one wore out.

When I went back to swimming after 25 years, I couldn't get past 75 yds without gasping for breath. I set the trained to 3 sec and went from 3 pool lengths to 50 the first day I used it.
The clip that holds it to the goggle strap broke and I used a rubber band on it.
Now I think the battery is gone.
Thanks for the idea of putting it inside the cap.
I'm getting another one.

I had a hard time hearing the beeps while I was swimming, so I do not feel it benefitted like I was expecting. I was hopping this would help me slow down my strokes.
Also, you have to be very careful how you store this, it is easily turned on by accident. Once the battery dies it can not be replaced nad you have to by another one.

this is our 5th tempo trainer, we have 5 kids.

My son claims he can hear it under the cap. I put in on a goggle strap and I can hear it occasionally when I turn to the side where this device is to breathe, not the other times.

If you turn it off after you are done using it the battery lasts longer