WAOAW Dog Anti-bark Collar for Small and Large Dogs Training with 7 Adjustable Sensitivity Control High-quality Electronic Anti-Bark Dog Collar and Sends harmless warning sound and shock to the dog whenever it barks This High-quality Electronic No Bark Dog Collar 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. 7 sensitivity levels (1-7) adjustable for the different size of dogs barking and specific environments through the "+" /"-" button. Lightweight receiver, Unique bark terminator, Effective on a 15-120pounds dog We suggest the buyer to test before use and 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