Description Description Alnor humidity and temperature probe designed for use with the TSI Alnor EBT721 balometer. Telescopic probe extends from 9 to 39 inches (230 to 990 mm) and isideal for measuring inside of duct work before and after a coil. Probe can be inserted into a standard 5/16 in. (8 mm) diameter hole typically used for pitot traverses and can be used to calculate wet bulb and dewpoint temperatures. State of California Proposition 65 WARNINGCancer and Reproductive Harm - www.P65Warnings.ca.gov. Literature & Docs Accessories