Under the lip, chin and throat, the fur is white but the chest and belly are a pale yellow with some irregular and rusty-red spots.

The species is named for the second lower molar (M2) being absent unlike in the least weasel.

However with a more thorough morphological examination of the skins and skulls, Colin Groves concluded it was a separate species.

[4] Very few samples have ever been obtained of this species, all from the mountains of the Shaanxi and Sichuan provinces of China.

The few individuals recorded have been found from 1,950 to 4,480 metres (6,400 to 14,700 ft) above sea level.