Small dogs have big barks, and sometimes they forget to use their inside voice. The PetSafe NanoBark 2.0 auto-adjusting bark collar puts smart bark control in a revolutionary small design to keep your home quiet and peaceful. NanoBark 2.0 dog collar responds only to your dog's unique voice and tunes out the neighborhood noise to help reduce nuisance barking. It uses patented advanced tech to deliver the minimum effective level of static and prevent your dog from growing accustomed to the correction. With a long-lasting battery and a comfort-first fit, it's perfect for just about anywhere.