The 2.80 Yuan stamp in the middle-top of the cover is from 2001 issue of Six Steeds in Zhao Mausoleum showing Steed Baitiwu.
Six Steeds of Zhao Mausoleum (Chinese: 昭陵六骏; Pinyin: Zhāolíng Liùjùn) are six Tang (618-907) Chinese stone reliefs of horses (1.7m x 2.0m each) which were located in the Zhao Mausoleum, Shaanxi, China.
Zhao Mausoleum is the mausoleum of Emperor Taizong of Tang (r. 626-649). The steeds were six precious war horses of Taizong.
Their names are: Quanmaogua (拳毛騧), Shifachi (什伐赤), Baitiwu (白蹄乌), Telebiao (特勒骠), Qingzhui (青骓) and Saluzi (飒露紫).
The sculptures are regarded as ancient Chinese art treasures. They were broken by smugglers in 1914 and two of them were shipped out. The stonework is exhibited in the Stele Forest museum of Xi'an (Shifachi, Baitiwu, Telebiao and Qingzhui) and museum of the University of Pennsylvania, USA (Quanmaogua and Saluzi) separately.