Acme 641 pea whistle is uniquely designed whistle combining the famous Acme Triller sound (High pitch Triller), with high pitch, single note, Airfast whistle, 60mm long. 

Listen to Acme 641

Some tips to train your dog with a dog whistle:

Firstly, get yourself a good Gun Dog and preferably an English Springer Spaniel, but the other Retrievers breeds will do :-)

* Use the dog whistle with varying sequences to train your dog. For example, one long burst can mean 'sit or Hup,' while a series of short, staccato bursts might mean 'come in to me,' or to turn when the dog is quartering in front of you.
Keep your whistle commands consistent and your dog will always know what you expect of him.

* The dog's behavior can be trained according to your instructions.

For example, at meal time, blow one long blast on the whistle and say sit/Hup before they get the food.This will let the dog know, they have to listen to a command.It will only take a few times of doing this and your dog will react quickly. When you are out in the field, the dog will know to sit when the whistle is blown once.

When doing this for the first time, you can reward the dog with a small treat when they react correctly to the command. After a little while of doing this, they will then react without the need for a reward.