Keep unfriendly dogs away; protect yourself from dangerous dogs while walking, jogging, or bicycling; Stop dog approaching you before it can bite you; A good protector for yourself; Also can be used to train dogs and bring you more fun; Need a 9V carbon battery (not included) Safe, humane and effective dog repeller; Can works with most dogs; Emits piercing ultrasonic tone that dogs hate and make dogs away from people.
Attention: No battery included  
The size may have a slight difference due to manual measurement.
Chaser - Choose " Chaser" switch, press the "ON" button emits ultrasonic, dog will be afraid of getting close to you. Train - Switch to choose "Train" gear, press the "ON" button emits ultrasonic to train your dog Light - Choose "Light" switch gear , it can be used as a flashlight.
High Power Ultrasound Double-head ultrasound for greater efficiency
 
Portable Size - Easy to bring outdoors hiking / home / training
 
INSTRUCTIONS FOR USE Attention: No battery included