Measurement range: 0 to 100 degree Celsius When put the item on the water, it works automatically, the LED lights and LCD backlight always flash during item working time Flash LED Lights are decorative of the item, but LCD backlight works as a warning backlight for the parents of little children Colorful LCD screen With temperature digital Yellow backlight lights when water temperature is lower than 35°C to warn the temperature being low, green backlight works when water temperature ranges 35-39°C, this temperature is suitable for body bath Red backlight brightens to caution being too high when temperature is higher than 39°C When the water temperature is more than 100°C, LCD shows the letters of HH°C, when the water temperature less than 0°C, LCD shows the letters of LL°C After measuring, take the item out of water and wipe away the water of its bottom, it will turn off automatically and stop working When being used, if LCD backlight brightens faintly, that means the batteries have exhausted,please replace batteries with fresh batteries Packing method: blister card and color box are available, customized packaging is also acceptable