Kocher's mask.
Ball
C
C
D000776:Anesthesiology / Q000266:history* / Q000295:instrumentation; D006042:Goiter / Q000266:history / Q000601:surgery; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D008397:Masks / Q000266:history*; D013557:Switzerland