Copper-alloy, 1.82 grams, 27.42 mm. Circa 12th-13th century AD. A barrel key of Type III cast in copper-alloy, with a simple rectangular bit. The bow is florid with a double collar to the shaft. Reference: Wheeler, R.E.M. London Museum Medieval Catalogue 1940, reprinted Ipswich, 1993, fig.136. Very fine condition. Provenance: found Tilbury, Essex, UK.