Oternal Advanced Electronic Anti Bark Dog Collar with no Harm Sound and Vibration for Puppy and Medium-small Sized Dogs Weighing 10-35 Pounds, an no Shock Pet Training Device Safe and Humane collar, send no hurt warning beep and vibration to the dog whenever it barks, no shock and no pain collar, the stimulations repeat through 7 correction levels, the collar stops for 1 minute after it reaches the 7th correction to protect the dog Adjustable advanced electronic dog collar, 7 sensitivity levels (1-7), adjustable for the different size of dogs barking through the sensitivity button, the more sensitive, the easier it goes off. Replaceable 6-volt Battery, Lightweight collar, Not waterproof Main effective on a medium-small sized dogs weighing 10-35 lbs. The collar is useful for the 6-10 lbs dogs, but it is a little big for the small dogs, the dimension of the collar is 2.6(L) x 1(W) x 1.4(H) inches. Don't encourage you to use it for the big dogs/ large breed, especially exceed 40 lbs, because the small stimulation (vibration, no shock) for the large breed may not be too obvious effect. Troubleshooting steps and other pertinent information are as follows: The collar would beep and vibrate to the dog under the situation that the dog takes other behaviors which shouldn't trigger the collar, such as shaking head, scratching, running, the interference of other dogs' barking and so on. A: 1) The phenomenon is mainly caused by excessive sensitivity settings, you can adjust the sensitivity setting to a lower or lowest level. The more sensitive the collar sets, the easier to get triggered. 2) If the collar can't trigger when the dog barks, you can increase the sensitivity to higher level. 3) There are 7 sensitivity levels (1-7), it is set to 4 level automatically when you install the battery, you can increase/ decrease the sensitivity by the buttons " Positive " and " Negative " The dog collar does not work, or the dog doesn't respond to it. A: 1) You can blow into the sensing hole which is located in the middle of the bark collar, if the collar goes off and send the beep and vibration, that means that the collar is in good condition. Otherwise, it does not work. 2) Place the collar snugly underneath the dog's neck, and not on the side of its neck, if not, the dog may be doesn't respond to it. 3) Make sure that the electrodes are in the direct contact with the dog's skin. If necessary, it is advisable to clip or shave the dog's fur under the neck to insure contact. 4) If the collar can't trigger when the dog barks, you can increase the sensitivity to higher level. 5) when the dog is not in use, please take the collar off, remove the battery. If it is wet weather, the battery in the collar which is in standby state, it may destroy electronic components and affect the life of the collar and the battery.