DOG CARE Dog Training Whistle, Metal Long Distance Training Whistle, Silver Color, 2 Inches Long, Used for Different Training Process Popular ultrasonic dog training whistle recommend by many dog trainers Quickly help you train your dog to stop barking and follow simple commands You need to firstly training your dog to do the right thing,such as the sitting, coming, stop barking, toilet training etc. then the whistle will be useful Adjust the whistles frequency to find the most effective sound for your dog Small and Lightweight, easy to use