Rh Dry Cabinet C15 Series has an adjustable humidity range (15-50% RH). This kind of dry cabinet box is designed to protect measuring devices, electronic devices, PCBs, medicine, some metal materials, and so on. And please also note that the dry cabinet could only remove the humidity, and could not add humidity. And the Dry Box Desiccator C15 Series has two series, C15U and C15B.