by Joe » Thu Feb 28, 2008 6:24 pm
I use an acme 211 and half whistle, the 211 and half is the code relevant to the pitch of the whistle, of which there are a few. I would also purchase a couple. I did have 4, (one for working, one in car, one at home and a spare) I have 1 left.
My advice also would be not to use string to put the whistle on, use something that will give easily, I had a bad experience with a branch and the string, when out working one of my dogs.