The Baro-Thermo Hygrometer is used with the OSI Wireless Weather Station WMR112A to monitor indoor atmospheric pressure, temperature and humidity. Operation is easy and no wire installation is required. SENSOR 0 0 G C B mb/HPa °C D reset inHg °F F H E 1 GB GB MAIN FEATURES: A LCD 4 line display indicates weather forecast, pressure, temperature and humidity. B °C/°F SLIDE SWITCH Selects between Centigrade (°C) and Fahrenheit (°F) C mb/hPA or inHg SWITCH Selects between mb/hPA or inHg D RESET BUTTON Returns all settings to default values E BATTERY COMPARTMENT Accommodates four AAA-size batteries F BATTERY DOOR G WALL-MOUNT HOLDER Supports the remote unit in wall-mounting H REMOVABLE TABLE STAND For standing the remote unit on a flat surface 4. Press the [°C/°F] button to select degrees display in either Fahrenheit (°F) or Celsius (°C). If degrees are displayed in Fahrenheit, press the [mb/hPA inHG]button and select "inHG" for display of humidity in inches. If degrees is displayed in Celsius, press the [mb/hPA inHG] and select "mb/hPA" for the humidity display. Slide battery compartment door back into place over the battery compartment. To see the readings from the Baro-thermo-hygrometer sensor you need to own the Main Unit of the WMR112A set. The main unit displays atmospheric pressure readings, indoor temperature and relative humidity. INSTALLATION 1. To access the battery compartment, slide the battery compartment door in the direction of arrows screws. Lift the top of the unit off from the base. shown on the compartment door. Insert 4 "AAA" size batteries (included) with the polarities in the direction as shown inside the compartment. Press the [RESET] button...