Size Main unit: 12.5*2*12.5cm, Secondary Unit: 5*3.7*10.5cm. [Three Channel Wireless Sensor - With built-in console and three remote sensors, this thermometer can display both room temperature and three sets of outdoor temperature and humidity. You can place it wherever you want. [Large LCD display and backlight] - Large LCD display for simple and clear readings. When a temperature or humidity alarm condition is triggered, the receiver corresponding to the warning color lights up and is accompanied by a snapping alarm sound for 5 seconds, the corresponding alarm icon will continue to flash until the temperature and humidity conditions are no longer valid, in the absence of operation, every minute, the receiver corresponding to the warning color lights up and is accompanied by a alarm sound clattering for 5 seconds, press any key to stop the alarm. [Signal strength and comfort display- Wireless transmitter allows 1000m travel strong signal. The signals from the main unit and the transmitter can be received freely. Comfort symbols indicate air conditioning - Wet / Fair / Dry. 50% RH (Dry), 15.6-26.7C, 50%-70% RH (Comfort), 70% RH (Wet). [Multiple Installation Methods - Easy to install. The presenter can be suspended or standing. The thermometer requires 3 AAA batteries (not included) and each transmitter requires 2 AAA batteries (not included). We only sell the thermometer, not other items in the picture. < p>Due to the difference between monitors, the photos may not reflect the actual color of the item. Please allow for small errors in size due to manual measurement.