Extremely rare, impressive & antique master humidity control or controller. Made in USA during 1930s. Made by The Bahnson Company. Amazing steampunk look and incredible quality.Excellent and antique original condition. I suppose it works, however I removed cable for security reasons (instrument includes original cable, so you can reconnect it). Diameter of glass cylinder: 5 inches. All defects not mentioned but visible in the pictures will be considered as described. If you have any question, do not hesitate to contact me. Thank you for your visit. The item "ULTRA RARE & ANTIQUE MASTER HUMIDITY CONTROLLER BY THE BAHNSON CO. IMPRESSIVE" is in sale since Friday, March 8, 2019. This item is in the category "Antiques\Science & Medicine (Pre-1930)\Scientific Instruments\Other Antique Science Equip". The seller is "liancollect" and is located in Buenos Aires, Buenos Aires. This item can be shipped worldwide.