Genial, there's nothing better!

Not flashy, not overly loud.
We have conditioned our dog it already as puppies,
There are breeders that even at the puppies do.

There are dog owners who look somewhat piqued and see this whistle, as a drill instrument.
You mean it does not need and wonder,
when they pointed to the whistling lips that
the dog times 'listens' and sometimes not.

Declaration; Man himself never whistles such as a whistle, namely always in the same frequency.

If you lose a times, sounds the newly purchased just naturally.
Assuming you bought back the same frequency (211.5)

Easy to care for as they are,
Just clean with a toothbrush under warm water times.

From the dishwasher, I advise, the cleaner might be too spicy but in the long run.