Size 25 x 30 mm.
Weight 7 g.
Reverse
第一潜水戦隊 - First Submarine Squadron http://hush.gooside.com/Order/GF/ss.html
昭和九年 - 1934
Original case.
Watch fob was made by Hattori workshop https://asiamedals.info/threads/history-labels-i-marks-of-hattori-watch-shop-tokyo.19361/
Obverse
賞 - Award
reverse
海軍兵学校 - Naval Academy
In the center
勝て兜の緒を締めよ = 勝って兜の緒を締めよう
"After victory, tighten your helmet cords" i.e. even after a victory, prepare for the next battle and do not let your guard down.
At the bottom
通信 - Signaling/Communication
Original case.
Watch fob...
award badges
imperial japan naval academy
japanese imperial navy badge
japanese naval badge
japanesenavybadges
勝って兜の緒を締めよう
勝て兜の緒を締めよ
海上自衛隊呉教育隊バッジ
海上自衛隊呉教育隊章
海軍兵学校章
海軍兵学校賞章
海軍兵学校體操體技賞章
體操體技賞章