Fieldpiece ARH4 Digital Sling Psychrometer Accessory Head<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Measures Temp and RH percent</li><li>Calculates wet bulb and dew point temperatures</li><li>Get outdoor dry bulb and indoor wet bulb for target superheat calculations</li><li>Log relative humidity over time and troubleshoot systems</li><li>English and Metric units</li></ul></div><img src="http://ecx.images-amazon.com/images/I/31tMIxZKr-L.jpg" noproxy>