This iron case would have held a bamboo triangular pen. Based on the high quality of execution it was clearly commissioned for a high Tibetan official. The loops would have been strung so that it could be carried on a belt or over the shoulder. For further pen cases of similar design, see Morning Glory (publ.), Precious Deposits, Historical Relics of Tibet, China, 2000, vol. 5, pp. 27-31, cat. no. 5.