Region in Placemark LineString The LineString box is visible between ~4000km and ~500km. The LineString corners mark the extent of the Region LatLonAltBox. The LineString minFadeExtent (at greatest range) is 1/4 of the maxFadeExtent (at closest range).. Region LineString 50 45 28 22 128 1024 128 512 22,50,0 28,50,0 28,45,0 22,45,0 22,50,0