HKM-367187 Ultrasonic Dog Training Whistle for Effective Obedience Commands - Metal & Plastic, 80mm LengthIntroducing the HKM 367187 Ultrasonic Dog Training Whistle, a reliable tool designed to streamline your dog training sessions. This whistle combines the durability of metal with the lightweight nature of plastic, measuring a convenient 80mm in length. Its unique ultrasonic frequency is inaudible to human ears but resonates perfectly with your dog, making it an ideal communication tool for various commands such as sit, come, and eat. What makes the HKM