Fischer Instruments 111-01 Stainless Steel 4" Human Hair Hygrometer The 111-01 is a laboratory grade human hair hygrometer for accurately measuring indoor and outdoor conditions. The stainless steel housing is vented for fast and accurate readings when mounted inside or outside in a shaded, protected area. Includes suspension eye for easy wall mounting. The Fischer factory for precision instruments was founded in 1945 by aircraft engineer Kurt Fischer, in a small village in the Erzgebirge called Drebach. Distributed exclusively in the USA by Ambient Weather, this piece includes a two year warranty.