A diffusion pump is a type of vacuum pump in which a vacuum is obtained by a stream of a pumping medium - vapors of boiling oil or mercury.
Hanff & Buest – manufactory
ca. 1930, Berlin
Jagiellonian University Museum Collegium Maius
Inventory number: 4265; 265/V
https://muzea.malopolska.pl/en/objects-list/2757