Anti-bark dog collar uses static correction, sound and vibration to curb undesirable behaviors. Highly effective and safe way to train your dog. Provides a slight tingling sensation intended to startle, but not hurt, your pet. Has 7 levels of static correction, vibration and sensitivity so pet parents can select the appropriate setting. Size is adjustable from 8 to 21.5 inches (20-55 cm), for dogs over 11 pounds (5 kg).