Arab-Byzantine, a Byzantine Follis of Constans II, countermarked bi-ludd on reverse, 5.44g (Goodwin B1b). Host coin and countermark fine.
Reference: Goodwin, T., 'Countermarking in Seventh Century Syria, Part II: Countermarks from after the Arab Conquest', Supplement to ONS Newsletter 183, 2005
Estimate: £40-50