This is a version of the signal the conductor on a platform is showing, when a train should depart. It only uses rigid vertex groups. It is the version which was in use in former Yugoslavia and still is in use in most the successor countries Croatia, Serbia, Bosnia etc. The small holes of the signal are not part of the geometry, they are simply transparent areas in the texture. So it is possible to create other signal e.g. for police by simply changing the texture.
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