During the Tang dynasty zhadou or 'leys' jars were made in various materials, as represented by three zhadou of comparable size illustrated by W. Willetts, Foundations of Chinese Art, London, 1965, pp. 286-7, nos. 181-3. They include a silver example in the Kempe Collection (no. 181), a blackish-brown-glazed example bearing a painted date corresponding to AD 841 in the Ingram Collection, and a Xingyao porcelain example in the Royal Ontario Museum, Toronto. Although each is somewhat different in shape, each has an elegant profile, as does the current example which is enhanced by its rare pale green glaze.