1. HIGH-ACCURARY TEMPERATURE HUMIDITY GAUGE – We pre-calibrate the sensor to make it extremely accurate! The indoor temperature range is +14.2ºF~+122ºF, the outdoor temperature range is -40ºF~+158ºF, the indooroutdoor humidity range is 20%~95%, the temperature accuracy is +-1.8ºF and the humidity accuracy is +-5%. 2. DISPLAY 3 SENSORS DATA, TRANSMISIION 328FT100M – Unni has advanced patented wireless technology that provides more powerful and steady data transmission. Wireless temperature humidity monitor updates and transmits temperature and humidity data up to 330 ft radius every 30 seconds, that will help you monitor all the locations you care about the most. 3. SPECIAL FEATURES – Stop worrying about the climate! You will be able to know in real time indoor and outdoor temperature and humidity with trend, Switchable °C &°F, Comfort indicator, Outdoor Temperature & Humidity Alert, Daily MAXMIN data, Low battery indicator. 4. USB&BATTERY POWERED, 4.5 INCH DISPLAY & ADJUSTABLE BACKLIGHT – Plug into the USB cable, which will keep the backlight on and adjust 3 kinds of brightness(high-low-off). The display is compact and easy to read with black, bold information. With a tabletop or wall-mountable design, you can place it in a location that is accessible and easy for you to view.