Removable heel is a concept that allow to easily change heels of a shoe during the day in order to change height, color or shape of the heel.
Changing height allow to lessen health effects of high-heels
History
First imagined in 1956 by French shoe designer André Perugia
Several brands tried to launch the concept in the 80' and 90' without success.
After 2010, several brands succeeded to manufacture and sell removal heeled footwear, like Tanya Heath Paris, Kathrin Lieber, Day2Night.
References
Removable heel Wikipedia(Text) CC BY-SA