This dongle can be used to to send a (different) EDID to the VGA output of an graphics card. The EDID contains information about the frequencies the connected VGA monitor can handle. This can be useful if you want to force the use of different frequencies the monitor does not advertise, or if the connected monitor does not have any EDID functionality on its own.

Be warned: The use of an incorrect EDID (i.e. unsupported frequencies) might damage your monitor. Use at your own risk.

My use case is to store an EDID for 15kHz modes, to drive the output to my VGA->SCART adapter (UMSA - Ultimate SCART Adapter) used to connect the TV in my arcade cabinet.

15kHz EDID images can be found at: https://github.com/Ansa89/linux-15khz-patch/tree/master/edid

A prerequisite for this to work of course is that the graphics card and its driver support the modes stored in the EDID.

The jumper on the board can be used to switch on/off the write protection of the EEPROM (which can also be written to via the VGA port).

A 3d-printable case for the dongle can be found at: https://www.thingiverse.com/thing:4719404