See also https://asiamedals.info/threads/1933-kanto-large-air-defense-maneuvers-koishikawa-ward-air-defense-corps-participation-commemorative-badge.25039/ Size 34.5 x 30.5 mm. Thickness 2.6 mm. Obverse 關東防空大演習記念 - Kanto Large Air Defense Maneuvers 参加章 - Participation Badge reverse...
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