Like yong zhong, bo zhong were made for use in graduated sets, and according to Jenny So in Eastern Zhou Ritual Bronzes from the Arthur M. Sackler Collections, Arthur M. Sackler Foundation, 1995, p. 381, bo zhong and niu zhong appear to have displaced the graduated set of yong zhong after the 5th century BC.
A bo zhong of larger size (62.2 cm.), cast with a very similar handle formed by a pair of addorsed birds, is illustrated by C.F. Kelley and Ch'en Meng-Chia in Chinese Bronzes from the Buckingham Collection, The Art Institute of Chicago, 1946, pp. 81-3, pls. XLIV-XLVI. However, unlike the taotie mask design decorating the striking area of the present bell, the Buckingham bo zhong is cast with a pattern of interlaced stylized dragons. Taotie mask designs can, however, be seen on two bells from sets of bells of early 5th century BC date recovered from Henan Hui Xian, Shanbiaozhen M1, and Shanxi Taiyuan, Jinshengcun M251. See J. So, ibid., p. 382, fig. 78.2 and p. 383, fig. 78.3, respectively. See, also, the similar, but larger bell (42 cm.), sold in these rooms, 24-25 March 2011, lot 1254.