jgibv:i got a couple of thesehttp://www.cigar.com/cigars/viewcigar.asp?prod=M-HYG10 they've worked perfectly for me. i always calibrate them out of the box to make sure they're correct, the adjustment dial is easy to use. i have them in different humis, so i'll check them against each other about every 6 months and they're always accurate. battery lasts about 2 years.
jd50ae:I saw one in a photo by Irishman +90 and I use one in every humidor. I put the all in a salt bag (they do not need calibrating) just to see if they were all close. heck, they all read the same. And it is the "CALIBER IV ROUND ADJUSTABLE DIGITAL HYGROMETER". IMHO it is well worth the $25 and is far better then any analog I have used.