Original Apple external GB (UK) region Express Modem DAA (Data Access Arrangement) for use with the Apple Express Modem board on the PowerBook 100 range and PowerBook Duo range. This allowed generic modem functionality to be built into the laptop with region specific circuitry and connector provided by the DAA.
NOTE: Although the connector is the same as the standard, serial or printer port, it should only be connected to an internal FAX/modem board.