Hiado Ultrasonic Flea and Tick Repeller Collar for Cats and Dogs, Anti Fleas Ticks, Natural Treatments of Controlling and Prevention Insect Flea & Tick protection Veterinarian Recommended Non-greasy, odorless, Can hang to pet neck directly Neck: 7.9"-21.6" / Unit size: 2.6"x0.8"x1.2" / Include: 3pcs AG13 batteries