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. Such a set of four bronze se rui, of mountain shape, was found in the late second century BC tomb of the King of Nanyue, and is illustrated in Xihan Nanyue Wangmu, vol. II, Beijing, 1991, pl. 48 (1). Several others, of various designs, 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 with down-turned petals (nos. 5 a&b), which retain traces of string wound around the square socket. Another, excavated at the Han tombs at Mancheng, which is stylistically similar to the present example, is illustrated in Mancheng Han mu fajue baogao, Beijing, 1980, vol. 1, pl. 50 (2).