A large limestone slab lying flat on the ground, face up and exposed to the sky, is not how most armorial carvings were meant to spend their existence. This one, found at the western end of a nave in Kilkea Demesne, measures roughly 80 centimetres tall by 60 centimetres wide and carries an intricate heraldic composition worked in false relief, a technique in which the design is raised from the background rather than deeply cut into it. It records, in stone, a particular moment in the life of one of Ireland's most prominent dynasties.

The plaque bears the arms of the Fitzgeralds, the great Anglo-Norman family whose influence across Leinster stretched back to the twelfth century. The central element is a heater-shaped shield, so called for its resemblance to the base of a flat iron, topped with a helmet and a lynx. Flanking the base of that main shield are two smaller shields, each displaying the Fitzgerald arms impaled with those of another family; on the left, Fitzgerald alongside Keating, and on the right, Fitzgerald alongside Geidon. In heraldry, impalement of this kind typically records a marriage alliance, placing two family coats side by side on a single divided shield. Beneath the composition are the initials I K and S G, with the date 1630, suggesting the plaque was cut to commemorate specific individuals and their connections to the Fitzgerald line at that moment in the early seventeenth century.