Ultrasonic Anti Barking Device Ultrasonic Stop Barking Device with 4 Sensitivity Adjustable Levels USB Rechargeable Dog Bark Control Color: green Material: ABS Waterproof level: IP45 Working distance: 50 feet / 15 meters How e it : The device can be charged in three hours and will work continuously for 30 days . When charging the device ,the digital display will show the power level and continue to flash until it is fully charged .When the product is fully charged ,the digital display will show a“4” . Before turning on the device unplug the USB charger. Turning the device ON-OFF To turn device ON press the“POWER” button down for 3 seconds and it will beep once with the digital display flashing a green number which will then disappear . To Turn device OFF press the“POWER”button down for 3 seconds and it will beep twice and turn itself off. Settings: .The digital display shows the levels ofsensitivity and Frequency. .You can choose to adjust the sensitivityfrom 1-4 by constantly press the Sensitivitybutton .  Level 1 is the least sensitive and level 4is the most sensitive. .You can choose to adjust the ultrasonic Frequencyfrom 1-4 by constantly press the Frequencybutton. Level 1-ultrasonic Frequency 15KHZ ,digital display 1 with 6seconds Level 2- ultrasonic Frequency 20KHZ ,digital display2 with 6seconds Level 3- ultrasonic Frequency 30KHZ ,digital display3 with 6seconds Level 4- ultrasonic Frequency will emit for 1-3 level 3 different ultrasonic frequency sounds with  6seconds ,digital display 4.