I bought it with a set with an offset holder. By covering the hexagon socket head bolt, the irregularities on the upper surface of the holder are gone and it is refreshing. It will be nice because garbage will not accumulate in the recess.
It is just the purpose of hiding the bolt, but it looks beautiful if it exists. It is easy to attach, but I will be careful not to hurt to remove it. Well it is disposable. It seems that plating is also solid.