Product review (5 stars): Great temp/humidity pen!
This is a a great device, I work for a mold remediation company and this is essential to our inspections.  We get the temp and humidity reading within just a few seconds of turning it on and use the data between indoors and out to determine if there is a water intrusion issue.  I does take about 10 seconds after turning on to deliver an accurate reading and is also best if not held in your hand when being used as it will cause a slight variance in the result.