The BC-50B is efficient and economic. Recently re-designed to protect you dog from over stimulation. How does it work? The stimulation levels increase every time your dog barks. After your dog has stopped barking for a 5 minute period, the No-Bark collar automatically sets the next stimulation back two levels. Thus enforcing the training method of the bark collar. The Lightweight Collar is designed for dogs from 20 to 200 lbs. This No-Bark system electronically detects the Bark of your dog, not just any dog or any bark. It then gives your dog a negative static correction. Your Dog quickly associates the barking with the correction. Usually it only takes a few corrections and your dog will stop on its own. To assist your dog in learning the system is pre-programmed with a three second “relaxation break” between corrections. The system operates on an easily replaceable 6-volt battery which is included. This is an ideal and safe solution for the problem barker. The neighborhood loud mouth will quickly become the neighborhood's model citizen. The BC-50B can be safely used outdoors or indoors.