Train Your Dog Instantly. Whistle sound stops anti-social behavior usually within 2-3 days. Safe and effective for all sizes and breed of dogs. Simply attach Tweeter to your dog's lead and walk your dog. When he pulls on the lead, a non electric whistling tone is emitted from the Tweeter which along with a verbal command will correct anti-social behavior fast and safe. The reliable, non-electric, humane dog trainer! Measures 5.5 x 1.25 x .75 inches and includes retail packaging.