Because a new federal safety regulation says that firefighters must have a clear view of how much air is left in their self-contained breathing apparatus (SCBA), LEDs are being used to illuminate the indicator. The LEDs are easy to see through smoke and also function as a warning system to other firefighters. When operating normally, the LEDs give off a blue-green light; if assistance is necessary, the LEDs give off a yellow color. The series of LEDs selected for this task use a low amount of power, which means fewer battery replacements. For more information, go to the following website: www.ledtronics.com.