Slave’s collar

A wooden slave collar was called quauhcozcatl in Nahuatl.
Sahagún states that under the day sign One Death, slaves received special treatment from their masters, including removal of “the wooden collars, the curved ones in which they were held and with which they went about restrained lest they flee.” [Fray Diego] Durán describes these cumbersome devices as wooden or metal collars with small rings through which were passed rods about a yard long. Not only did these fetters immediately identify the wearer as a slave but they also hindered quick movement in a crowd. This was necessary because, according to Durán, if a slave could escape from his master in a market and run outside the limits of that marketplace before being caught, and then immediately step on human excrement, he could obtain his freedom. The escapee would then present himself to the purifiers of slaves and demand his rights under the law of the land. Washed, and presented with new clothes, he was praised for his skill and enterprise and was given a whole new start in life. Such a person was considered lucky and often was kept in the palace as a retainer.

Quote from The Codex Mendoza by Frances F. Berdan and Patricia Rieff Anawalt, vol. II, University of California Press,1992, p.206.
Image sources:-
• Image from the Codex Mendoza scanned from our own copy of the James Cooper Clark facsimile edition, London, 1938
• ‘Tlatelolco Marketplace as depicted at Field Museum of Natural History, Chicago’, photo by Joe Ravi (Wikipedia Creative Commons Share-Alike License CC-BY-SA 3.0).