FITCAMX dash cam includes brand-new methods for powering from an auto-dimming rear view mirror with hidden wiring and quick installation using the plug-to-plug approach. There is no need to remove the A-pillar and connect the car fuse box to the cigarette lighter. G-Sensor can detect abrupt crashes while driving and promptly store the appropriate lens footage to the file to avoid overwriting, saving your video proof. When the card hits capacity, it will automatically replace the older videos with the most recent ones.(Maximum supported SD card size is 256GB). When the car begins, the dash cam immediately turns on. When the car is locked, the dash cam immediately turns off.