Physical description

2x IUD/Gräfenberg's rings. The ring was introduced by German gynecologist Ernst Gräfenberg in 1929. It ceased to be in wide use circa 1939. Inserting a foreign device into the uterus causes an inflammatory response, which creates a hostile environment for sperm. The silver wire used to construct later versions of Gräfenberg's ring was contaminated with copper, which increases this spermicidal effect. These two are most likely from the late 1960’s.