During the Imperial German Period, hooks & eyes, buttons, and snap buttons were an important part of securing uniforms. Zippers were not yet in use for trousers, and so items like this were commonly used to secure them. Six of these snap buttons are on the original sales card. These date from about 1900-1910. Even if you do not need them to secure a uniform, they would make a fine addition to a display showing how these items were sold and used.