Product review (5 stars): Excellent quality for the price.
I purchased 2 of these units for monitoring humidity and temp levels in gun safes. Out of the packaging, both units had the same temp and humidity readings. Periodic calibration proved that both units stay within 1/2% (one half of one percent) of each other. The Extech meters are as stable and accurate as much more expensive test meters.

Pros: Stable and accurate readings, especially for the price.
Cons: Sensor wire probe is only 18".

I would definitely recommend the Extech.