recently purchased these ballusters from stair parts USA. price was fair compared to the big box stores. shipping was very reasonable, and took only a few days. they are well made, and look beautiful, however, when I tried to find whatever the part it is that attaches the balluster to the rail, I came up short and had to "get creative" and figure out how to attach the "square" end to the railing. I looked EVERYWHERE and could not find anyone that knew what this part is. I attached some photos of my installation so you can see what I'm talking about. other than that, super happy with our purchase!