If so, you are intitled to a free calibration kit. Its an easy way to check the calibration of your Avallo Accumonitor. You can also use it to check your other hygrometers. Just send me a private message with your name and address, and I will ship one out. You can see some more info on it at www.cigarsolutions.com. Go to the Accumonitor page, and click on the calibration instructions.