This is a box of black ink cartridges for Kaweco Fountain Pens. 6 cartridges included.
Since 1883, Kaweco has been making geometric fountain pens mechanical pencils, rollerballs, and ballpoint pens in Nuremburg, Germany. Their Classic line 'Sport' was created in the 1930’s for the ladies, officers, soldiers and sportsmen with the goal of having a pen that could be carried easily without a dress pocket.