Copper-alloy, 3.75 grams, 38.90 mm. Circa 12th-13th century AD. A barrel key of Type III cast in copper-alloy. The bit is a rectangle with toothing on the leading edge. The key is robust, with a slightly thickened leading edge to the shaft. Reference: London Museum Medieval Catalogue 1930, reprinted Ipswich, 1993 p.136 and plate xxix (1). Very fine condition. Provenance: found County Durham, England 2008.