It is not especially large, measuring just over a metre and a half in length and tapering slightly toward the base, but its design is precise and considered. A Latin cross occupies the face, its angles hollowed out to create a subtle concavity at each corner where the arms meet the shaft, and the lower shaft splays outward to form a natural base. A narrow rebate, roughly five centimetres wide, runs down each of the long sides, framing the composition. The slab also has a faint hog-backed profile, meaning it curves gently along its length rather than lying perfectly flat, a quality that is easy to miss until you look at it side-on.

The scholar R. A. S. Macalister, writing between 1916 and 1917, catalogued this stone and placed it within a twelfth-century tradition of Irish cross-slab carving. Inis Cealtra, a small island in Lough Derg on the Shannon, was one of the more significant early Christian monastic sites in the west of Ireland, and the Saint's graveyard would have been a place of considerable ritual importance within that community. Cross-slabs of this kind, flat or gently shaped stones incised or carved with a cross rather than fully sculpted in the round, were a common way of marking graves or commemorating individuals throughout early medieval Ireland. The particular combination of features here, the hollowed angles, the flared shaft, the rebate, places this example within a recognisable decorative vocabulary that was still in use as the island's monastic tradition moved into its later medieval phase.