Fairway Markers indicate the distance (in yards) from the Marker in the fairway to the center of the green. Some courses use a sunken and anchored, colored metal disk in the center of the fairway as a marker.
Others may use a colored pole set back from the fairway a distance, with an opposing pole of the same color directly on the opposite side of the fairway. Sometimes a course may have opposing shrubs or trees of different types used as markers.