Opaque modern face mask (used until late 1980s). Upper row: Unidentified generic mask, Ohio Medical Products conductive mask, Rush antistatic mask, Everseal mask (Medical and Industrial Equipment Ltd., United Kingdom). Center: Rendell-Baker-Soucek pediatric mask. Transparent face masks. Lower row: Ohio Medical mask (cca. 1970), Intersurgical silicone face mask (Intersurgical, Ltd, United Kingdom), symmetrical generic Artificial Manual Breathing Unit (AMBU)-King mask (King Systems/AMBU, USA), asymmetrical ergonomic face mask (Tuoren Medical Group, China). Picture taken by Adrian A. Matioc, M.D., at the Wood Library-Museum of Anesthesiology, Schaumburg, Illinois, with their kind support.