About 11th Army and its wound badge see https://asiamedals.info/threads/wound-badge-of-11th-army.23369/
1st type.
Size 35x28 mm.
Obverse
長期奉公 - Long Service
reverse
第十一軍 - 11th Army
Original case.
長期奉公章 - Long Service Badge
Another cased specimen of 1st type.
11tharmy long service badge
imperial japan armybadgejapanese11tharmybadgejapanesearmybadgejapanesebadge in the form of the shield
japanese military badge
第11軍長期奉公章
第十一軍長期奉公章