On the round disk, edged with a moulded rib, are the figures in relief of Emperor Constantine and his mother St Helena in the posture of prayer and with a cross between their nimbi. Another relief cross is on the beak, and a third at the bottom of the ring base. The form of the lamp is Asiatic and has no direct analogies in this territory, and the scene on the disk is typical of representations based on Christian iconography. The lamp was probably made by some travelling craftsman in Singidunum itself, which was a cathedral town at that time. It may have been commissioned by a local priest and intended for a church.