It measures roughly 1.27 metres in length and 0.46 metres across, and cut into its surface is a deeply incised cross that runs almost the full length of the stone. The cross has what are called hollowed angles, where the spaces between the arms are scooped out rather than filled, and its shaft is open-ended, meaning it does not terminate in a defined foot. A portion of the top is now grassed over, making the full design a little harder to read at a glance.

What makes this slab quietly peculiar is that it appears to have slipped through the net of formal scholarship. When the archaeologist R. A. S. Macalister surveyed and published his plan of the adjacent Saint's graveyard in 1916 and 1917, he drew this stone into his plan but assigned it no number and offered no description of it. The cross incised on its surface went unrecorded in his published account, despite being clearly visible. The slab sits just 8.18 metres from the northern wall of that graveyard, close enough to have been well within view. Inis Cealtra itself, sometimes anglicised as Inishcaltra or called Holy Island, is one of the more significant early medieval monastic sites in Ireland, and its cluster of churches, grave markers, and enclosures represent centuries of religious activity in the Shannon region. That a carved graveslab here could be drawn and yet left undescribed says something about how much detail these sites contain, and how much can remain effectively invisible even after a careful survey.