Ambient Weather 118-01 Fischer Instruments Laboratory Grade Indoor/Outdoor Thermometer with Human Hair Hygrometer The 118-01 is a laboratory grade thermo-hygrometer for accurately measuring indoor and outdoor conditions The stainless steel housing is vented for fast and accurate readings when mounted inside our outside in a shaded, protected area The hygrometer includes a set screw for calibrating the humidity The hygrometer includes a set screw for calibrating the humidity Includes mounting hook for easy mounting