The 2.1.9 Tuscan round series iron baluster features a single 2-1/2″ knuckle. This baluster is solid wrought iron and is 9/16″ round on the ends. It uses the shoes for the nine sixteenth inch balusters 16.3.26 and 16.3.27. This single knuckle baluster pairs with all other Tuscan round series balusters.