Note: The faceted shape and long, slender neck may derive from faceted Yue ware vases from the Tang dynasty (ad 618-907). Two examples of faceted hexagonal Yue ware vases, also with slender necks, one from Fufeng County in Shan'xi province, dated to AD 874, and the other, excavated from the Tang dynasty Shanglinhu kiln site in Zhejiang province, are illustrated by Lin Shimin, Celadon and Yue Kilns, Shanghai, 1999, nos. 68 and 69 respectively. Both vases lack the shaped handles found on the present vase.
A vase of similar shape, also with a Yongzheng mark, was sold at Christie's New York, 23 March 2012, lot 2102. Compare, also, the Yongzheng-marked Ru-type vase of very similar shape and of approximately the same size, from the J. M. Hu Family Collection, offered at Sotheby's, New York, 4 June 1985, lot 56.
A slightly smaller vase (9 7/8 in.) of similar shape, but with a celadon glaze and an unusual early Qianlong seal mark, in the Wang-Xing Lou Collection, is illustrated in Imperial Perfection: The Palace Porcelain of Three Chinese Emperors, Hong Kong, 2003, pp. 186-87, no. 69.

Christie's. Sacred and Imperial: The James and Marilynn Alsdorf Collection Part I, New York, 24 September 2020