It measures roughly 46 centimetres across and only 10 centimetres tall, a low, carefully shaped disc with rounded mouldings and a hollow chamfer, the latter being a bevelled groove cut to receive and seat a circular column of 36 centimetres in diameter. The edges have been broken in several places, suggesting either a rough removal from its original setting or a long and careless afterlife before anyone thought to record it properly.

What makes this fragment quietly compelling is not its size or condition but what remains visible on its upper surface: the mason's circumference guidelines, the faint scored lines a medieval or early modern craftsman drew directly onto the stone to mark out exactly where the column shaft would sit. These working marks were never meant to be seen. They were practical notations, the equivalent of a pencil line to be covered over once the column was in place. That they survive at all is a small accident of the fragment's fate, removed from its building before the column above it could obscure them forever. The piece is catalogued under the Kilkenny depot reference KD018 and is associated with the townland of Leggetsrath in County Kilkenny, though the original structure it belonged to is not recorded.