The piece measures just 0.33 metres long and 0.12 metres wide, and its inscription, rather than carved in the conventional sense, is pocked along one of the corner edges in the characteristic notch-and-line system of ogham, an early medieval script used primarily in Ireland between roughly the fourth and seventh centuries to record personal names, usually on standing stones that marked graves or territorial boundaries.

The stone came to light when a field fence in the townland of Brookhill, near Tralee, was demolished. It had been built into the wall as ordinary fill, the way many ancient stones were reused once their original meaning or function was forgotten or no longer relevant. The fragment was apparently broken in antiquity, well before it ended up in that fence, so the inscription it carries is incomplete. What survives reads, with gaps on either side: A MAQ LUG. In ogham formulae, MAQ is the Primitive Irish word for "son of", cognate with the later Irish Mac. LUG is almost certainly a personal name, likely derived from the god Lugh, a common enough element in early Irish naming. The letters preceding A and following LUG are lost, meaning both the name of the person commemorated and the full name of the father are now unrecoverable. The stone is held by the National Museum of Ireland, catalogued under accession number NMI 1960:272.