It measures roughly thirteen centimetres in both height and width, and what survives on its visible face is, in the words of scholars Okasha and Forsyth, "no more than the end of an arm", the faint remnant of an outline cross with expanded terminals. The original form of the slab is unknown; what remains is a fragment of something larger, now embedded in the fabric of a medieval wall.

The stone came to light during excavations at the site in 1944, recorded by Duignan, and was subsequently catalogued as Toureen Peacaun 17. Cross-slabs of this type, flat stones incised or carved with a cross motif, are among the more common early medieval commemorative or devotional objects found at Irish ecclesiastical sites, though most survive in better condition than this example. The expanded arms of the cross, where each arm widens slightly at its tip, are a recurring feature of early Christian stonework in Ireland, found across a broad range of dates and regions. That only a sliver of the carving remains makes it difficult to say much more about the original piece, but its incorporation into the church wall suggests it was recognised and preserved rather than discarded when the building was modified or repaired.