Obverse 高雷爆 - Advanced Course in Explosives /Depth Charge/ reverse 皇紀2603年 - 1943 第十八期高等科 - 18th Advanced Course 兵器整備術 - Weapon Maintenance 雷爆練習生卒業記念 - Explosives /Depth Charge/ Trainee Graduation Marked 純銀 - pure silver.