Features: There are many computers controlling car with modern electronic control systems. When the computer powered off or the level changed, part of the information stored in the car computer will be lost. To prevent this phenomenon, the power off memory of the car computer used to keep the memory of the car computer, such as dashboard information, digital clock, stereo, electric rearview mirror, etc. When the battery changed, the memory of the car computer will not be lost. Save times and improve efficiency. It has the functions of power indication, undervoltage indication and overload protector. The diagnostic seats directly connected to the car computer, with directly connection, power supply indication and undervoltage indication. The 12V battery used for power supply, which absolutely that the car computer settings will not be lost when replacing the battery, and avoids the failure of power supply with 9V dry battery. The product contains fuses to protect the car computer from accidental damage. Check whether the connection with the car normal. If there a green light, it indicates that the communication between the helper and the car normal. Test the indication of the standby battery. If the voltage of the standby battery insufficient, a red light will be on for warning. If the communication with the car normal and the power supply battery sufficient, two green lights will be on. you can safely change the car battery. Specifications: Material:ABS Note: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1Set Battery Memory Saver