The is not a single file, but rather a generic term for the USB-to-Serial drivers required to make this diagnostic cable work. Because the CP105B is often a generic clone device, users must determine if they have a genuine FTDI chip or a clone Prolific chip to ensure they install the correct driver version. Once the correct driver is installed and the COM port is properly configured, the CP105B serves as a cost-effective tool for basic automotive diagnostics on older vehicle models.