Mount your MS XL rails securely onto sturdy light stands with this Spigot Mounting Plate for MS XL System from Waterbird. The durable steel adapter provides a standard 5/8" mounting option to the stand and a 3/8"-16 threaded top screw for mounting onto the bottom of the rail segment. The manufacturer recommends using one spigot mounting adapter with a separate stand at approximately every 39" of track.