Phoenix Synchro-IR beacons  are a series of infrared beacons that flash in unison to mark a specific line, landing zone and personnel (Combat ID). The beacons emit a covert signal that is visible at long ranges when viewed with night vision devices. All Synchro-IR Beacons can either be a leader (to program other Synchro-IR Beacons) or a follower (to receive a program and synchronize to the leader). This capability allows all follower Synchro-IR Beacons to flash the exact pattern as the leader, and identify units precisely instead of random IR flashing.