PetSafe Ultra Light Sonic Bark Control Pet Training System

The Ultra Light Sonic Bark Control unit emits a loud sound that startles your dog, disrupting his barking and discouraging him from continuing. While very effective, it is perfectly harmless.The Ultra Light Sonic Bark Control unit, the lightest and smallest on the market, attaches to your dog's existing collar, so he doesn't have to wear a second collar.Adjustable sensitivity level allows you to adjust the system to your dog's unique bark.Complete system includes:Receiver (1 oz., 1.9 cubic inches): can be attached to your dog's existing collar (one inch width or less, non-metallic).Operations manual.Training manual.6-volt battery module.