D-Wiz Dog Whistle to Teach Your Dog How to Stop Barking. Special 2 Pack Offer Use to train your dog and have as a bark control for dogs You can teach a dog new tricks with the D-Wiz! Teach your dog commands or to stop barking, use this to whistle to your dog Adjustable high pitch dog whistle frequency to specifically target your dog's hearing This is NOT a silent dog whistle so that you can know how loud or soft you want your dog to be hearing it. Comparable to Ortz and CLD Brands dog whistles, also as effective as Acme dog whistle. 100% Satisfaction Guarantee or your money back!