The refers to the Microcontroller Unit (MCU) software used in many "unbranded" or universal Chinese Android head units. Specifically, the CVD1810-WJ version is a common identifier for devices running on platforms like the AC8227L.
Many of these units use XYAuto components. You can check the XYAuto File Database (Username: Xyauto / Password: 123456 ) for version-specific MCU updates. cvd1810 firmware link
A commonly cited download for the CVD1810-WJ firmware can be found on this Shared Google Drive . The refers to the Microcontroller Unit (MCU) software