Convert from sadzhen to hair's breadth

Unit Definition (sadzhen)
The sadzhen is a traditional Russian unit of distance corresponding roughly to the English fathom and French toise. Early in the 1700s, Czar Peter the Great fixed the length of the sadzhen at exactly 7 English feet. This equals 3 arshin or 2.1336 meters. Sagene is an older transliteration of the Russian word.

Unit Definition (hair's breadth)
The hair's breadth is a common informal unit of distance. Human hairs vary considerably in width, depending on age, color, genetics, and other factors. An average hair is approximately 70 to 100 micrometers (µm) in diameter, so, as a rough standard, a hair's breadth is 100 µm or 0.1 millimeter (mm).