Inside lighted, LSDS are designed to provide the pilot, the runway distance remaining from the runway end in thousands of feet and the position of the pendant cables for arrester hook engagement, either by day or night. Colors may be white or yellow on black background depending on the application. It is designed in compliance with FAA AC 150/5345-44. Messages can be on one or both faces as there are four barrettes of 12 LEDs, two each side of the sign, for optimum luminance of both the faces.