Put an end to nuisance dog barking with our Intellipet Bark Solver! Bark Solver units can be wall- or shelf-mounted inside or out. An ultrasonic correction tone sounds each time dogs bark. Sensitivity adjustment controls how loud the bark must be to trigger the tone. Frequency adjustment allows for selection of either ultrasonic sound (inaudible to most humans) or a sound audible to both dogs and humans. Standard Bark Solver X25 controls barking within 25 feet and includes a wall-mount bracket, an AC adapter, a protective vinyl cover for outdoor use, and an extra long 50' cord for long-distance performance. Measures 5 1/2"L x 3 1/2"W x 1 1/3"H. Bark Solver X25 includes a one-year warranty. Bark Solver X40 designed for outdoor is also available and sold separately.