The F-117 is made "low observable" in a few different ways. The first is with flat, angular exterior panels which are set to reflect radar returns away from the transmitter. The F-117 also uses radar absorbent material (RAM), which is epoxied to the basic aluminum structure. Finally, the placement of the engine, the use of screens over engine intakes, and the flattened structure of the exhaust nozzles are designed to further reduce reflectivity and infrared radiation.
