Features:  Dog Training and Barking Control Devices -The ultrasonic dog barking control devices can correct dog's bad behavior . Ultrasonic frequency is 20-30 KHZ , it can grabs your dogs’ attention , 100% safe for dogs. Great for Small/Medium/Large Dogs: The dogs barking control devices effective for dogs of all breed 3 in 1 Dog Training Barking Control Devices: the bark control device has 3 modes. "Sound " "Ultrasonic " and "Flash light".You can starting with "sound" mode first, if it no effect,then try to “ultrasonic ”or “flash light”mode. Rechargeable: The UItrasonic dog barking deterrent is rechargeable. it can full charge within 40 minutes, then works about 2 hours. Convenient & Portable: The anti barking device is small. It perfect for in the hands,and comes with an anti-static wrist strap. And you can carry it in your pocket. Notice: 1.Actual color may be slightly different from the image due to different light effect 2.Please allow 1-3cm deviation due to manual