The PetSafe Basic Bark Control Collar is a static electric bark collar with six auto-adjusting correction levels. The collar has 6 levels of low to high static stimulation strengths. When your dog barks, the collar delivers a static stimulation at the lowest level (level 1). If your dog continues to bark within 30 seconds of the previous bark, the collar automatically increases one level at a time until it reaches the highest level (level 6). When your dog is silent for 30 seconds, the collar resets to the lowest level of correction (level 1). Each static stimulation is also accompanied by an audible tone.