Product review (5 stars): Excellent Value and Accurate
Purchased this make along with two other similarly priced brands on amazon that all appear to be made by the same manufacturer. Placed them all in a zip lock bag containing a charged Humi-Care crystal gel container for a week, along with a much more expensive Zederkoff and Xikar models and they all registered + or - 1 point of each other. Ran the test one moth later and same results. Bottom line is that these are pretty darn good devices and the price can't be beat.