So I was very happy to receive this gift for me to review, the whistle comes on a lanyard which I keep hanging on the dog leash hangers. When I am ready for them to come in I just give a slight whistle and they come right in.
I like the whistle because it is not loud like a coaching whistle that the gym teacher carries, instead it is a higher pitch and makes just a little sound. You can even use it at night without bothering the neighbors.
I definitely recommend purchasing one of these if you are like me and just cannot whistle.
You can get yours here on Amazon: http://amzn.to/1e8TXo3