
The number of aircraft warning lights recommended per level depends on the shape and size of the building (L - W):
L and W < 45m
4 obstruction lights shall be used (one per corner)
45m < L < 90m
1 additional obstruction light shall used in the middle of L (see the picture)
L and W > 90m
the lights shall be spaced at longitudinal interval not exceedeing 45m
The number of aircraft warning lights levels depends on the height of the building (H):
H < 45m
1 level of low intensity obstruction lights shall be used
45m < H < 108m
2 levels of obstruction lights shall be used: top level with medium intensity obstruction lights, intermediate level with low intensity obstruction lights
108m < H < 203m
4 levels of obstruction lights shall be provided: 1st and 3rd levels with medium intensity obstruction lights, while 2nd and 4th levels with low intensity obstruction lights (see the picture)

The number of light units recommended per level depends on the diameter of the mast (D):
always
1 obstruction light shall be used on the top (see picture)
D < 6m
2 obstruction lights shall be used (on diagonally one per corner)
D > 6m
4 obstruction lights shall used (one per corner)
The number of obstruction light levels depend on the height of the mast (H):
H < 45m
1 level of low intensity obstruction lights shall be used (see picture)
45m < H < 108m
2 levels of obstruction lights shall be used: top level with medium intensity, intermediate with low intensity (see picture)
108m < H < 203m
4 levels of obstruction lights shall be used: top level with medium intensity, 1st intermediate level with low intensity, 2nd intermediate level with medium intensity, lower level with low intensity (see the picture)

The number of light units recommended per level depends on the diameter of the structure (D):
D < 6m
3 obstruction lights per level shall be used (120°)
6m < D > 31m
4 obstruction lights per level shall used (90°)
D > 31m
6 obstruction lights per level shall be used (60°)
The number of obstruction lights levels depend on the height of the chimney (H):
H < 45m
1 level of low intensity obstruction lights shall be used (see the picture)
45m < H < 108m
2 levels of obstruction lights shall be used: top level with medium intensity, intermediate with low intensity (see the picture)
108m < H < 203m
4 levels of obstruction lights shall be used: top level with medium intensity, 1st intermediate level with low intensity, 2nd intermediate level with medium intensity, lower level with low intensity (see the picture)

Wind turbine structure shall be lighted by mounting 2 flashing obstruction lights (medium intensity or BMVW type W) on the top of the generator housing.
Both obstruction lights shall flash simultaneously and shall be mounted at the horizontal separation to ensure an unobstructed view of at least one obstruction light by an aircraft approaching from any direction.
Intermediate lights levels and other marking maybe omitted on these structures.

Low intensity light markers should be use on transmission line catery wires near airport, heliport, across rivers.
The number of light units recommended per level depends on the diameter of the mast (D):
always
1 obstruction light shall be used on the top (see the picture)
D < 6m
2 obstruction lights shall be used (on diagonally one per corner)
D > 6m
4 obstruction lights shall used (one per corner)
The number of obstruction light levels depend on the height of the mast (H):
H < 45m
1 level of low intensity obstruction lights shall be used (see the picture)
45m < H < 108m
2 levels of obstruction lights shall be used: top level with medium intensity obstruction lights, intermediate level with low intensity obstruction lights (see the picture)
Year: 1989
SEGS60I
ICAO type A
FAA L810
Incandescence
Year: 1994
SEGS23E20
ICAO type A
FAA L810
Fluorescence
Year: 1998
SEGS23L07
ICAO type A
FAA L810
LED
Year: 2004
SEGS23L10
ICAO type A
FAA L810
LED
Year: 2006
SEGS23A32
ICAO type A
FAA L810
LED
Year: 2010
SEGS23B32
ICAO type A
FAA L810
LED
Since 1989 we have continuously innovated our aircraft light systems with the introduction in the market, after the traditional incandescent lamps, of at first the fluorescent lamps and after that of the low intensity LED lamps: since almost 20 years our research and development department has continuously developed new models of aircraft light systems reducing the consumption and increasing the reliability and lifespan of the lamps.
Year: 1999
SEGS23F60
ICAO type B
FAA L864
Xenon
Year: 2002
Prototype
ICAO type B
FAA L864
LED 5mm
Year: 2004
SEGS23L3K
ICAO type B
FAA L864
LED 5mm
Year: 2005
SEGS23L2K
ICAO type B
FAA L864
LED 5mm
Year: 2007
SEGS23P2K
ICAO type B
FAA L864
Power LED
Year: 2010
SEGS23P2K_10
ICAO type B
FAA L864
Power LED
Since 1989 we have continuously innovated our aircraft light systems with the introduction in the market of at first the xenon lamps, at second the LED lamps using a 5mm technology and finally the medium intensity LED lamps: since almost 20 years our research and development department has continuously developed new models of aircraft light systems reducing the consumptions and increasing the reliability and lifespan of the lamps.