Petiner Harmless Dog No Bark Collar for Anti Barking Control Collars-No Harm Warning Beep,Vibration and Shock (Black) NEWLY LAUNCHED VERSION - Petiner Bark Collar were improved in sensibility and service lifetime. It will more easily catch your dogs' barking,works for a longer service lifetime. HUMANE AND EFFECTIVE - Progressively increasing warning sounds first,Then harmless static stimulus,repeat through 7 correction levels,For your dog's protection,the bark collars will stop working for 1 minute should your dog continue to bark. EASY TO USE - Simply slip it around your dog's neck and the system will work automatically. EASY ADJUSTABLE SENSITIVITY LEVEL - 7 levels adjustable for different size of dogs barking and specific environments through the "+" /"-" button. FITS MOST BREEDS - For almost virtually any dog in between, To help guarantee the safety and comfort of your pet, we generally recommend the collar for dogs ranging from 15- 120 lbs