Oternal Electronic No Bark Control Dog Training Collar with Slid Button Adjustable Sensitivity Control, Black Nylon Collar, an and Effective Pet Training Device for 8-120 Pounds Dog, Keeping a Quiet Environment At Home/Indoor (2015 Upgraded-improve Sensitivity Setting, Appearance, Battery Life, Etc.) High-quality Electronic No Bark Control Dog Collar and Sends harmless warning sound and shock to the dog whenever it barks The stimulations repeat through 7 correction levels, the intensity gradually increases until the dog stops for thirty seconds. If the continuous stimulus reaches the 7 levels, then the Collar will stop working for 1 minutes to protect the dog Slid button sensitivity levels freely adjustable for the different size of dogs barking and specific environment Lightweight receiver, Unique bark terminator, Replaceable 6-volt Battery, Effective on a 8-120pounds dog NOTE: Don't encourage you to use it for puppy, especially below 8 lbs, but you maybe can have a try carefully. If the dog is too small, you must use it under the guidance of the master to avoid unnecessary harm to your dog, because the stimulation for the puppy will be a little strong