The stone sits on a slightly off-centre platform on top of the cairn, and what survives of its ogham script, the ancient Irish writing system that uses a series of notches and strokes cut along a central stemline, breaks off frustratingly mid-word, leaving only a partial name and a trail of damaged stone where the rest once was.

The cairn occupies a spur running north-west from Drung Hill, positioned on the boundary between Gleensk and Kilkeehagh townlands, which also marks a parish boundary. The site goes by the name Laghtfinnan Penitential Station, suggesting a long association with religious observance and ritual movement through the landscape. The stone itself stands 1.06 metres at its maximum height and is relatively slender, measuring 33 centimetres by 20 centimetres at its base. The inscription runs along the north-east angle of the stone. When the scholar R. A. S. Macalister examined it in 1945, he could make out the opening of what appears to be a genealogical formula common to ogham inscriptions: MAQI, meaning "son of" in Old Irish, followed by the letter R and then a scatter of vowel notches before the stone surface flakes away entirely. Roughly eight and a half inches of inscription are simply gone, scaled off with the stone, and only a single vowel notch survives beyond the damage. What name the stone was originally commemorating remains unknown.