Our stair balusters are made of high-hardness aluminum alloy, featuring excellent anti-rust and corrosion-proof properties for indoor/outdoor uses. The sturdy structure and rustproof coating provide stability and durability. A #19 drill bit is included for easy, secure, and elegant installation. | Vevor | | Staircase Balusters 51 Pack, 36 In Aluminum Stair Balusters, 3/4 In Water-Proof Round Metal Spindle Railing | Black | Best Buy