Oternal Electronic No Bark Dog Training Collar with no Harm Warning Beep and Shock for the 15-100 Pounds Dog (Black) This advanced anti-bark dog collar sends harmless warning beep (tone) and static shock to the dog whenever it barks, keeping a quiet environment at home/ indoor With full automatic controlles, the stimulations of the collar repeat through 7 correction levels, the intensity increases gradually, till the dog stops barking for thirty seconds. If the stimulus reaches the 7th correction level continuously, the collar will get into dormant state for 1 minute to protect the dog 7 sensitivity levels (1-7) are adjustable for different conditions, such as different sizes of dogs and dogs barking as well as specific environment. The more sensitive, the easier to make it trigger Not waterproof, Lightweight receiver, Replaceable 6-volt battery, Black nylon strap with 30.5 inches length Effective on a 15-100 pounds dog. Don't encourage you to use it for puppy, especially below 10 lbs, but you maybe can have a try carefully. NOTE: 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. And the dimension of the collar is 2.8 x 1.4 x 1.4 inches, which is a little big for the small dogs.