My Hajari a Rhodesian Ridgeback comes back to me when ever I use a whistle. Sadly I lost mine somewhere and did a search for a replacement. Looking at several sites selling Acme I came across Canine Concepts and found it difficult to choose which one to have. The Web site is clear and displays these in several colours with concise explanations on each whistle's function. Oh!, which one shall I choose? and in the end it was blue with a matching lanyard. Your service was excellent and the goods arrived in perfect condition to me in France. I am back to being safe with my dogs knowing that they will always be back with me when I call. Thank you Canine Concepts.