Request for token identification (military token)

Please help me identify this token.
I know that it was used in 9th Cavalry Regiment in the United States, but I desperately need other information, such as what country it was used in.

The design is very similar to many Vietnam tokens:

https://www.ebay.com.my/itm/285144342188

https://www.etsy.com/listing/1170098250/yung-tau-nco-open-mess-token-from-the

https://picclick.com/Token-US-Army-NCO-Open-Mess-186768954793.html

https://www.ebay.ca/itm/285117452124

So I would guess 1960's Vietnam.

9th Cavalry history page: https://1cda.org/history/history-9cav/

Thank you for your answer.
It looks similar to the U.S. military token used in Vietnam, but the U.S. military token used in Japan and Korea also looks similar. I don't think it's a matter of judging just by appearance. However, it is true that the unit was stationed in Vietnam, so I think it is likely to be a military token used in Vietnam.

From this reference by Paul Cunningham has it linked to Tokkae, Korea

21mm

Reference number - KR2960b

KR2960a is 10¢ and has an Indian on a horse on one side. 18mm

KR2960b is listed as Plated Brass. Also, the token I have doesn't have an Indian on a horse.