It is neither obviously a font nor quite anything else, and that ambiguity is precisely what makes it interesting. Measuring roughly 85 centimetres long, 55 centimetres wide, and 40 centimetres high, with a shallow basin cut into its upper face, it looks functional, deliberate, and yet curiously incomplete.

Patrick Healy, writing in an unpublished Office of Public Works report from 1972, catalogued the piece as a granite font and recorded its dimensions carefully, including the basin, which measures approximately 58 centimetres by 38 centimetres and is about 20 centimetres deep. He noted two significant absences: there is no draining hole in the basin, and no dowel hole that would have been used to secure a cover. Those missing features matter. A baptismal font typically has provision for draining water after use, and many were fitted with lockable covers to protect the blessed water from misuse. Without either feature, this object may instead have served as a water stoup, a basin placed near the entrance of a church where worshippers could dip their fingers in holy water before entering. Stoups in early medieval Irish ecclesiastical sites were often simple, unadorned stone vessels, and the position of this piece, just inside the doorway of the cathedral, would suit that function well. Glendalough, sometimes referred to historically as Sevenchurches after the number of ecclesiastical remains clustered in the valley, was one of the most significant monastic sites in early Christian Ireland, and its cathedral is the largest of the surviving structures there.