{
  "version": 8,
  "sources": {
    "mapbox": {
      "type": "vector",
      "url": "mapbox://mapbox.mapbox-terrain-v1,mapbox.mapbox-streets-v5",
      "maxzoom": 14
    }
  },
  "layers": [{
    "id": "contour_line_loud",
    "type": "line",
    "source": "mapbox",
    "source-layer": "contour",
    "filter": ["==", "index", 5],
    "paint": {
      "line-color": "#008",
      "line-width": 0.9,
      "line-opacity": "no"
    }
  }]
}