"THE TRANSMITTER, LASER GENERATES SIMULTANEOUSLY MODULATED INFRARED (IR) OUTPUT IN IR BANDS I AND IV USING POWER AND TIMING SIGNALS SUPPLIED BY THE RECEIVER, COUNTERMEASURES. IT INTERFACES TO THE RECEIVER, COUNTERMEASURES USING BI-DIRECTIONAL ASYNCHRONOUS COMMUNICATIONS FOR COMMAND AND STATUS MONITORING. IT PERFORMS AUTONOMOUS CONTINUOUS BUILT-IN-TEST (BIT). IT IS AIR COOLED."