Sometimes, it is the back mark that makes a button interesting or stand out. This button is marked GESETZLICH GESCHUTZT which means copyrighted or patented. The three stars signifies quality. I haven't seen this back mark before I found this button in a sort. This labeling was not used in Germany until 1899. Possibly, turn of the century button. The front of the button is incised brass accented with a mother of pearl center. Button has a sturdy wire loop shank.