The Premier Pet Rechargeable Bark Collar discourages barking for all size dogs. If your dog barks, the collar detects the vibration of your dog's vocal cords and issues a gentle static correction. This correction will not be triggered by the bark of any dog except the one wearing the collar. With 15 levels of automatically adjusting static correction, this anti-bark collar ensures your dog receives the best level for his/her temperament. The correction will start at the lowest level and will only increase if barking persists. No programming required! This rechargeable, waterproof collar has a nylon strap that is adjustable up to 28", making it a great fit for both smaller and larger dogs. A low battery indicator on the collar will alert you when the collar battery should be replaced. A built-in safety feature will automatically shut off the collar for 3 minutes if your dog barks 15 times or more within a 1 minute 20 second period. Live peacefully together with your dog, small or large, by discouraging barking when using the Premier Pet Rechargeable Bark Collar!