For your consideration is this Taylor Instruments Sling Psychrometer in great condition. It comes in its original packaging, some of which has not been opened. These are used to measure relative humidity for various applications. I have not tested it. Instructions on how to use it, can be found online. The instrument is about 12" long, with a 4" handle. Look over my photos to judge the condition for yourself. Shipping via USPS Ground Advantage will be calculated from 53095, for a package weighing 1lb 4oz. I'm embarrassed to say this, but I was not able to fold the handle down. I'm sure it's supposed to fold down and fit into the plastic sleeve. I will ship it as seen in the photos. Thanks for taking a look.

Taylor Instrument Companies, Sling Psychrometer-Measures Relative Humidity- XLNT