Type K

To operate all aerodrome lighting for a duration of approximately 15 minutes, key the microphone 7 times initially. This will ensure all lights are on maximum intensity. The intensity may be adjusted up or down to any one of three settings by keying the microphone 7, 5, or 3 times within 5 seconds for high, medium, or low intensity settings respectively. The timing cycle may be restarted at any time by repeating the initial keying sequence. Where runway identification lights (code AS) are available, keying the microphone three times on the appropriate frequency will turn them off.