The inscription reads OR[ÓIT] AR MAINACH, an abbreviation of the Old Irish oróit ar, meaning "a prayer for", followed by the name Mainach. It is a formula found on early medieval carved stones across Ireland, a quiet petition scratched into rock so that those who passed might intercede for the named soul. What makes this fragment quietly remarkable is how long it went unnoticed in its proper context, and how straightforwardly it was misattributed by some of the most respected antiquarian scholars of their era.

The slab belongs to a group of eight cross-slabs associated with Leaba Bhreacáin on Inis Mór, the largest of the Aran Islands. A leaba, in this context, is an early ecclesiastical bed-shrine, a low rectangular structure of kerbing stones that marked the resting place, real or symbolic, of a saint. This particular fragment forms part of the western kerbing of that monument. Scholars including Petrie, Crawford, and Macalister each recorded it as being located at Teampall Bheanáin, a small early church on a different part of the island entirely. The error was noted by Waddell in 1973 and confirmed by Higgins in 1987, a reminder that even careful fieldwork, conducted without the benefit of systematic survey, could place an object convincingly in the wrong spot for generations. Only a portion of the slab now survives, measuring 0.5 metres high, 0.41 metres wide, and 0.12 metres thick, with two incised lines marking what remains of the cross shaft and the inscription cutting across it.