See also badges of the same design https://asiamedals.info/threads/greater-japan-civil-defense-association-saitama-branch-special-merit-badge.26929/ ; https://asiamedals.info/threads/saitama-prefecture-keibodan-badge.24748/
Bakelite.
Width 32 mm.
Obverse
埼 for 埼玉県 - Saitama Prefecture...