[New Model] Vastar AD630 Dog No Bark Collar Electric Anti Bark Shock Control with 7 Levels Button Adjustable Sensitivity Control, Stimulation of No Harm Warning Beep and Shock for 15-120 lb Dogs The Vastar new model bark collar were improved in sensibility and service lifetime High-quality electronic anti-bark dog collar and sends harmless warning sound and shock to the dog whenever it barks 7 sensitivity levels (1-7) adjustable for the different size of dogs barking through the "+" /"-" button Lightweight receiver, unique bark terminator, replaceable 6-volt battery and low battery consumption, effective on a 15-120 pounds dog We don't encourage you to use it for puppy, especially below 8 lbs., but you maybe can have a try carefully