A Ketoh is a heavy wrist band to protect an archer from the snap of the bow string.
Originally they were plain thick leather straps. Once silvermsithing became a part of Navajo life, ketohs began to be decorated with silver and stones, usually turquoise.
Ketohs were made by and for Native Americans, not the market. Now there is no practical use for these wrist guards but they are worn on special occasions by both men and women.
The bow guard shown in these photos is vintage (1970s) but unused.