Tired of barking dogs disturbing your peace and quiet? Whether it\'s your neighbour\'s dog or your own, this advanced ultrasonic bark stopper has proven highly effective. Triggered by barking within a 20m sq. range, the unit emits an ultrasonic noise that\'s inaudible to humans yet uncomfortable for dogs and in most cases, the barking will stop or be greatly reduced. Cordless weatherproof unit 3 settings; flashing LED, ultrasonic noise or both together. 3x AA batteries (not supplied). H24cm inc. spike.