This is an elephant ivory pax of the Holy Trinity, made in France (Paris) or possibly England in the second half of the fourteenth century. It depicts the Holy Trinity and the relief is worn smooth, presumably by kissing, in the area of Christ's head.

A pax is a tablet or board, sometimes of silver, usually decorated with a Christian religious representation. A pax was used at the end of mass as part of the ‘Kiss of Peace’ ritual after the Angus Dei. First the priest would kiss the tablet, then the members of the congregation. England was precocious in introducing the pax, but references abound elsewhere from the beginning of the fourteenth century onwards. Paxes could be made from many materials, including wood, copper, silver and gold, as well as ivory.
The earliest, fourteenth-century, examples are invariably decorated with the Crucifixion, but the imagery rapidly diversified to take in other scenes connected with the Christ’s Passion and Sacrifice. By the fifteenth century the choice had expanded, with many scenes of the Virgin and Child.