The Company of Animals High-Frequency Whistle is lightweight and compact with an adjustable pitch – ideal for dog walking and training. Find the tone that’s best suited for your dog by adjusting the pitch. Producing a sound that travels well in open spaces, great for distance training and recall. The high-frequency pitch of this whistle is particularly appropriate for noise-sensitive breeds such as Border Collies. For ultimate convenience, the High-Frequency Whistle is small enough to attach to your keys or wear on a neck lanyard.