Solid polished brass barrel with a black dial, this Maximum Comfort Minder tracks both inside temperature and relative humidity. It is completely self-contained and designed for indoor use. There are no external wires or sensors, this Comfort Minder is mounted on a Mahogany Instrument Panel. The panel is 8" square and the brass barrel is 6" in diameter.  Overall it is 3" thick

Relative humidity is an indication of how water-saturated the air is. Changes in relative humidity can have a substantial effect on your comfort level. The Comfort Minder is a highly accurate instrument and calibrated to /- 5% relative humidity.

This is used - and looks unused