Automatic Bark DetectionIt will automatically detect the tone of your dogs bark & will be active while your dog barks and once barking halts the device will switch off. Safe and EffectiveDog barking control devices emits a high frequency sound when your dog barks & then immediately turns off when your dog stops barking. This sound is nothing humans can hear and it isn't strong enough to hurt you or your dog's ears. Durable & WaterproofDog barking control devices waterproof resistant with easy installation solutions. Can be hung anywhere in the house or even outdoors on a tree, wall etc. RechargableDog barking control devices is completely wireless which can be used wherever suits. Please charge for 5 hours prior to using. 3 Levels of IntensityMultiple levels of intensity to suit all breeds & sizes. Low, mid & high frequencies depending on situation.