MaximalPower Dog Repeller Helps to eliminate barking and annoying behavior of dogs using the ultrasonic frequencies from this device which is very safe for the dogs and human Uses new innovative method of Advance calibrated sonic and ultrasonic frequency waves to drive dogs and mosquitoes away Protects yourself from unfriendly dogs while doing your outdoor activities like jogging, walking, Cycling or working without having fear of stray Can also be use to train dogs and repel mosquitoes using the sonic frequencies. It is non-toxic and chemical free