It is a window jamb, the vertical side-piece of a window opening, retaining its glazing groove, the narrow channel cut into the stone to hold a pane of glass or, in earlier centuries, leaded glazing. The fragment measures just 28 centimetres high, 36 centimetres wide, and 15 centimetres thick; modest dimensions that give no obvious indication of where it once belonged. That it has ended up as part of a garden feature, mortared in among ordinary rocks, is a quietly odd fate for a piece of worked medieval stonework.

The jamb is believed to have come from the medieval Dominican friary that once stood in Tralee. The Dominicans, a mendicant order of friars who arrived in Ireland during the thirteenth century, established a presence in the town, and their friary would have been a substantial complex of church buildings, cloisters, and ancillary structures. Window jambs of this kind would have been routine components of such buildings, carefully shaped to frame openings in thick masonry walls. When the friary fell into ruin or was demolished, its dressed stonework was dispersed, as frequently happened with suppressed or abandoned religious houses across Ireland, the cut stone being reused wherever it was useful. This particular fragment eventually found its way into the garden of the church that, in a sense, succeeded the friary's community on the same ground.