Best Brand Of Dog Whistle?

[Beaglelover:)]

Sniffing around for a good dog whistle.

Is it best to buy an adjustable whistle where you can customize the pitch to be most effective for the dog or does a general purpose one do the trick that isn't adjustable?

I do want a dog whistle not a plastic human whistle (if that makes sense).

Just wanted to ask where is the best place to buy them and if there is a brand preferred throughout the dog world?

Any help would be great.

Also posted in training forum.

[Tiggy]

I got the 'Training the whistle recall' dvd which came with a whistle. It's a pea-less whistle whatever that is. It's loud!