Fingerspitzenformer were supposed to sculpt unattractive fingertips into more slender, sexy ones. The user would simply place one of the five spring-loaded, felt-lined clamps on a fingertips and, in just ten minutes, presto, beautiful fingertips. Personally, I'm skeptical of actual results. Also, each clamp was the same size which meant that the same small clamp was meant for the fattest of thumbs, too. Ouch!
Based on the one fashion magazine advertisement that dates to 1925, I assume that these were produced within a couple years of then and for not much longer. Their advertised price was 3 Deutsche Marks for a set of 5.
Made by Unknown
Formes pour les bouts des doigts, which translates to "forms for fingertips," is written in French on the inside of the case's lid. Below that, in German, Fingerspitzenformer. These forms were made in Germany with intentions of appealing to the fashion (self) conscious women of France and elsewhere.