Finally - Barking Control for BIG Dogs! This Bark Control Collar is the most advanced dog bark collar ever made! This safe and effective bark control collar can’t be falsely set off by other noises or another barking dog and it features 18 total levels of correction with 3 selectable ranges. Within each range, there are six automatically incrementing correction levels. On the first bark, dogs gets the lowest, mildest correction. The corrections gently increase with each successive bark until dogs find the level that is sufficient to discourage dogs from barking. The unit deactivates if dog barks more than 50 times in a 30 second interval. 3-Volt replacement batteries are also available (see item ZT10800).