4 pcs. These are dual green LEDs with in-line 4 dip,  As far as I can find these were used in aviation displays and are rare.  I believe the configuration allows for high priority indication by alternating the LEDs in the bar.  This LED bar measures 10mm long 5mm wide and 6mm board height.  the pins are about 4mm and are standard IC distance. 

Thank you and God bless!