Feature:Material: PlasticSize: 8*6. 5*5cmUses ultrasonic sound to deter unwanted barkingDetects barks up to 50 feet with the use of an internal microphone4 levels of operation including a test modeDurable and weatherproof for outdoor useTow Color LED:Shows good or low batterySwitch with 4 Levels of Operation:Test-used to verify the microphone and speaker are functional1=Low Range-up to 15 feet2=Medium Range-up to 30 feet3=High Range-up to 50 feetHow The Outdoor Bark Control Works:When 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 control:Stop your barking dogStop your neighbors' barking dogTrain puppies not to barkDeter barking dogs on camping tripsNote:Keep at arms length away from the human ears to avoid hearing damage. if a dog begins barking while you are setting up,mounting or hanging the Outdoor Bark Control. If the dog is deaf or hearing impaired,he may not react to Outdoor Bark Control. Use this for Max 2-3 hours per day, Please do Not make it work all day long , or dogs will get immune to this, thus impacting the effect A 9-volt battery required(battery not included) includes:1 x Anti Barking Device