High Tech Pet Super Hush Puppy Progressive Stimulus Sonic Bark Control Collar Humane Operation: Uses no shock and causes no pain or discomfort to your pet Features unique, progressively increasing sound stimulus for quick, easy no-bark training; Water resistant; rain and snow will not affect operation Operates on a 6 volt alkaline battery (not included); Voice recognition feature minimizes false triggering High quality nylon strap adjusts from 5" to 24" Lightweight and Comfortable on Dogs Weighing as Little as 5 lbs;Effective on Dogs Weighing as Much as 150 lb or More!