A total of three modules may be used with the main receiver, one splashproof remote module included. Relative humidity range is 25 to 90% with a resolution of 1% and an accuracy of ±2% RH mid-range to ±4% RH elsewhere. Switchable thermometer range is –4 to 140°F and –20 to 60°C, with a resolution of 0.1° and an accuracy of ±1°C. Requires two AA and two AAA alkaline batteries (included), which should last about 8 months.
Note this unit does not come with the 10' external probe like the 4115 does.