Operating principle: change Interval interval of ultrasonic frequency conversion output reduces mouse hearing resistance and continuous flashing LED light to expel mouse and prevent rodents like mouse from biting the wire. Durable with variable ultrasound and thus protects against costly engine damage to the car. Operation process: 1 to 1 15 seconds, the red light flashes 3 times, then the 12K 25kHz ultrasonic wave is emitted, accompanied by the white LED flashes. 16-30s, ready to go employment. 31-50s, repeat process for 1-15s. 51s-1min 10s, ready to go employment. 1 min 11 s 1 min 40 s, repeat from 1 to 1 15 seconds. Stop after the above actions for 1 minute. Repeat the above actions twice and hold it for 3 minutes or 5 minutes. When the car starts, our device automatically goes into sleep mode and stops working. 5 minutes after stopping the car, the work mode is activated. to protect the car from pests such as mice. Detection function Low voltage battery monitoring: The product detects the battery voltage during operation. If the battery voltage is lower than 9.2V, the product will alarm and stop working to avoid battery power failure. When the battery voltage is restored, the alarm will automatically stop and go to sleep. Easy to use Install: When installing Simply connect the two plugs of the power cable to the positive and negative poles of the car battery and secure it with the cable ties provided. And it has reverse connection protection function. Prevent artificial circuit connection from damaging the product.