This fitting is similar to others that have been identified as zither string anchors (se rui), such as the example from the Therese and Erwin Harris Collection illustrated by J. So and E. Bunker in Traders and Raiders on China's Northern Frontier, The Arthur M. Sackler Gallery, Smithsonian Institution, Washington DC, 1995, pp. 150-51, no. 72, where the authors discuss the use of these fittings, and how they would have come in sets of four. They note that the early anchors were made of wood, but by the second century BC, were often cast in bronze. A set of four bronze mountain-shaped se rui from the late second century BC tomb of the King of Nanyue is illustrated in Xihan Nanyue Wangmu, vol. II, Beijing, 1991, pl. 48 (1). Several other fittings, of various design, in the Museum of Far Eastern Antiquities in Stockholm, are illustrated by O. Karlbeck, "Selected Objects from Ancient Shou-chou," BMFEA, vol. 27, Stockholm, 1955, pl. 41 (1-6), including a pair cast as a flower with six down-turned petals (nos. 5 a&b), which retain traces of string wound around the socket. Another very similar example is illustrated in Mancheng Han fajue baogao, Beijing, 1980, vol. 1, pl. 50 (3).