The badge has the same design as special member badge https://asiamedals.info/threads/special-member-badge.23257/
Only suspension has reverse color scheme and reverse insciptions are different.
Suspension of regular member badge.
Suspension of special member badge.
Early "heavy" badges...
dainippon airdefense association
full member badge
great japan airdefense association
japaneseairdefensebadge
regular member badge
大日本防空協会
大日本防空協会正会員章
大日本防空協会章
正会員章
great japan airdefense association
greater japan airdefense association badgejapaneseairdefense association badgejapaneseairdefensebadgejapaneseairdefense school badge
osaka airdefense school
osaka airdefense school badge
大阪防空学校
大阪防空学校章
This design was used for badges issued by Shitaya Ward to participants of air defense maneuvers in Kanto area during 1930s.
In 1936 badge with similar design was commissioned by Arakawa Ward Air Raid Defense Corps...