The A4133 is a convenient way to input data from a single 0183 heading sensor and generate 3 separate outputs:
1 and 2 are buffered versions of the input so as to feed two devices such as autopilot, radar and plotter or display
Output 3 is in AD10 format.  All 3 outputs include the 12V power for which the A4133 has a separate feed.  This feed and the input and all the outputs are in the form of screw terminals.