FeaturesUses ultrasonic technology to stop barks - More effective and durable. No more barking.Sensitive microphone for outdoor(waterproof) use. Can also be used indoors, recommended level for indoor use is level 1Four adjustable ultrasonic volume levels - test, low, medium, and high, with LED battery power level indicator.The product will not work on deaf or hearing impaired dogs. There are some situations where dogs become desensitized. To avoid this, only turn the outdoor bark control on during periods of unwanted barking.The device uses low-intensity ultrasonic, is silent to humans and not harmful. Safe for small, medium, large dogsHow The Outdoor Bark Control WorksWhen the outdoor bark control is within range of a barking dog,an internal microphone pick up the sound and the unit is automatically activated.The outdoor bark control emits an ultrasonic sound.the ultrasonic sound can be heard by dogs but is silent to humans.Startled by the high-pitched sound that is safe and effective,the dog should stop barking,it will associate its bark with this unpleasant noise.When the dog stops barking the ultrasonic sound also stops.The outdoor bark control has 3 range levels and a test mode.It is effective up to 50 feet.Possible use for the Outdoor bark controlStop your barking dogStop your neighbors' barking dogTrain puppies not to barkDeter barking dogs on camping tripsPackage IncludesNew Outdoor Bark Control and manual(Note: without battery)