Features: 1.The product suitable for cars,bedroom,and outdoor sport. A.For cars:It has luminous light, which is good for night driving. B.For bedroom:When you get up in the middle of the night,turn on the backlight on the back to check the time and temperature.There is no need to wait for a long time,the luminosity is moderate,the luminosity that the eyes can easily adapt to,does not affect sleep. C.For outdoor sport:When camping,it is light and small,and it is portable.If the network is not good,it can be used as a survival tool. Steps for setting time: 1. Clock function: There is 12/24 hour switching function (default is 12-hour system). 2. Clock setting: Press A key for 3 seconds to set the hour, press B to set the value, then press A to set the minute, press B to adjust the minute (adjust the minute to zero), then press A to confirm and exit the setting. (Press and hold the B button while adjusting the value, it can be speeded up. When setting, if there is no key pressed for more than 60 seconds, it will automatically confirm and exit the setting). Note: Power by 2 * AG3 cell battery (Not included) Please take out batteries and reload it again, if display is abnormal, and time need to be reset.