The slab is just under two metres long and tapers slightly from top to base, its edges chamfered in a workmanlike fashion. What makes it worth pausing over is the density of its imagery: the central carving depicts a cross and shaft rising from a stepped Calvary mount, the cross itself enclosed within a shield and formed by a crossed lancet and chalice, instruments associated with the Eucharist. Around these, carved in relief, are the Arma Christi, the symbolic "weapons of Christ's Passion", including a ladder, a hammer, pincers, two nails, a scourge with four flails, a seamless garment and three dice, the last three items referencing the casting of lots for Christ's clothing at the Crucifixion. A Crown of Thorns encircles the junction of the shafts, and INRI runs along the top of the shield. The concentration of Passion symbolism on a single funerary slab, arranged with such deliberate iconographic care, is a measure of how seriously late medieval Gaelic patrons engaged with Continental devotional traditions.

A Latin inscription in black-letter script runs in a rectangular band along the top of the slab and descends vertically down either side of the shield. Transcribed by the historian Carrigan in 1903, it reads: HIC IACENT DONALDUS OHEDYAN and FILIUS EIUS ANNO DNI M CCCC LII, which translates as "Here lie Donnell O'Heydan and his son, A.D. 1452." Beyond these few details, the O'Heydans remain elusive; their names survive here principally because someone had the means and the inclination to commission a slab of this quality from a mason clearly familiar with the iconographic conventions of the period. The slab is now cracked in several places, with three bad horizontal fractures and an additional vertical crack running between two of them, damage that gives the stone a fragile, provisional air despite its obvious solidity.