CUPET Ultrasonic Stop Barking - Voice-activated & Wall-mounted Dog Barking Silencer Pet Training Device Barking Control for Training Small Dogs (No Harm) ULTRASONIC HUMANIZED SOLVE DOG'S BARKING PROBLEMS: In general, only more than three times consecutive dog barks will trigger the pet training device. The device send out 5 seconds of ultrasonic. (People can't hear, dog can), the ultrasonic makes dog feeluncomfortable. (There is absolutely no harm to dog) After repeated many times, the dog will establish a conditioned reflex, won't easily bark. INSTALLATION NOTES: This machine is installed near the doghouse, the installation place isn't leak and wet, not easy to touch. The device cann't be inverted or horizontally mounted, to prevent effect sensitivity and reliability. Human ear can't close to the ultrasonic emission head (the eyes of the machine), to prevent discomfort. APPLICATION METHOD: After installed the device, plug in the power, The power indicator (green LED) is lit. At this time, if loudly simulate continuous dog barks, ultrasonic emission signals (red LED) is lit about 5 seconds. If the environment noise is too big or unused for a long time, turn off the power, to prolong the working life. SUITABLE FOR OUTDOOR & INDOOR: Perfect for use in hotels, restaurants, courtyards, garages and other places. Suitable for puppy and medium dogs, up to 50lb(25KG), Please be careful this. (Due to the environmental noise, size of the dog's voice, distance of the dog and device, we cann't guarantee that the stop barking success rate is 100%) EFFECTIVE RANGE: Dog and device of distance is within 2 meters, which is the most effective. If more than 4 meters, little effect. (Because a few dogs not sensitive or too small don't understand, which make the effect is not good to stop barking. And the more bold and temper is very fierce dog, hear ultrasonic, which makes it uncomfortable, the dogs will more bark.)