This car engine anti-theft device features an automatic sensing relay replacement system that eliminates the need for installation; it is concealed and difficult to detect. No operation is required in automatic sensing mode; it can switch between manual and anti-theft modes. It does not damage the car's wiring; installation is quick and easy. After the engine is turned off, the fuel supply is automatically cut off; when the vehicle approaches, the fuel circuit automatically opens; the sensing distance is approximately 15 meters. It employs anti-shielding and anti-interference technology; the chip performance is stable. It is only compatible with 12V gasoline vehicles. Features: Unit relay working principle: 1. First start: The device begins scanning the sensor ID password; if a match is detected within 25 seconds, the vehicle starts successfully. If no valid ID is detected within 25 seconds, the fuel circuit is cut off, and the engine shuts off. 2. Second start: Scanning time is reduced to 20 seconds. 3. Third start: Scanning time is reduced to 10 seconds. 4. Fourth and subsequent starts: If the correct password is not detected, the system determines it as an unauthorized start. The device will only allow the engine to run after detecting the correct sensor ID. 5. In hidden lock mode, continuous scanning will be disabled while driving; sensing needs to be restarted after the engine is turned off. Remote Control: Static Current: approx. 0mA; Operating Current: 5mA; Battery Type: CR2032; Relay Operating Current: approx. 20mA; Color: Black; Material: ABS; Package Contents: 1 x Relay; 2 x Induction Remote Controls; Note: Light reflection and monitor differences may cause the color of the items in the picture to be slightly different from the actual product. Size may have slight errors due to manual measurement.