It is not a large object, measuring roughly 0.8 metres by 0.6 metres and only 0.08 metres thick, but the carving on its face is precise and considered: two nested, roughly equal-armed crosses, each with forked and T-bar terminals, enclosed by two concentric circles around the central crossing point. The form is trapezoidal, wider at one end than the other, shaped from local sandstone. Cross-slabs of this general type are among the earliest forms of Christian stone carving in Ireland, typically associated with early medieval monastic sites, where they marked graves or served as devotional objects within a community's sacred space.

Inishkeen Island lies in Lough Scur in County Leitrim, and the slab was recovered from a spot on the island referred to as the Friars Garden, a name that implies a monastic or religious presence at some point in the island's past. The slab's carved design, with its forked terminals and concentric ring decoration, is characteristic of early Christian stone-working traditions in Ireland, though pinning down a precise date without further excavation context is difficult. It was recorded by A. T. Lucas in 1972 and described in detail by Herity and colleagues in 1997. At some point the slab was removed from the island and transferred to the National Museum, where it remains part of the wider collection of early medieval carved stones from across the country.