Although the exact function of the present lot remains unknown, it can be compared to the end cap of crossbows from the Eastern Zhou to Han dynasty, such as one excavated from a Warring States tomb in Luoyang, Henan province, fixed to the end section of the wood shaft remnants of a crossbow, published in Luoyang Museum, 'The Chariot Pit Found at Chung-chou-lu', Kaogu (Archeology), no. 3, 1974, pl. 3, fig. 1, (see p. 177, fig. 7 for the reconstructed diagram of a crossbow); one from the Warring States period, reported to have come from Jincun, Luoyang province, modeled in a similar form with an opening to one side for attachment, illustrated in William Charles White, Tombs of Old Lo-Yang, Shanghai, 1934, pl. IX, fig. 16; and another from the C. Vignier Collection, attributed to the Han dynasty, published in Umehara Sueji, Shina-Kodo Seikwa / Selected Relics of Ancient Chinese Bronzes from Collections in Europe and America, pt. III: Miscellaneous Objects, vol. I, Osaka, 1933, pls. 59a and c.
Another possibility is that the present lot may also be an architectural fitting. See two rectangular socket fittings of similar size, each attaching to a longer fitting, discovered in the tomb of a king from the Zhongshan State during the Warring States period in Pingshan county, Hebei province, included in the exhibition The Cultural Relics and Art of the Ancient Zhongshan Kingdom, Shanxi Museum, Taiyuan, p. 51; and a smaller socket fitting of rectangular form, attributed to the Han dynasty, illustrated in Pierre Uldry, Chinesische Gold und Silber, Zurich, 1994, pl. 90.