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...
dainipponairdefenseassociationbadgedainipponairdefenseassociationmembershipbadge
greater japan airdefenseassociationbadge
japanese airdefenseassociationbadge
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