Badge that could be easily confused with supporting member's badge https://asiamedals.info/threads/dainippon-air-defense-association-supporting-member-badge.23259/
Designs of both badges are identical, only reverse inscriptions are different.
Late war badge in light alloy and instead of...
dainippon air defense association badge
dainippon air defense association membership badge
greater japan air defense association badge
japanese air defense association badge
大日本防空協会普通会員章
大日本防空協会章
普通会員章