4. humidity resolution: 1% 5. temperature deviation: ± 1ºC 6. humidity deviation: ± 5% 7. using the battery: AAA 1.5V 8. size (circular): Ф 91mm 9.working environment: temperature 0 ~ 50.0 ºC, relative humidity ≤ 85% RH, no corrosion, no strong electric radiation. The basic functions: 1. Celsius / Fahrenheit switching display 2. the highest / lowest temperature humidity memory function 3. 24-hour clock 4. daily alarm clock function 5. calendar display function 6. 8 minutes snooze function The button function: MODE button: 1. Press to switch the display time/date. If the date is displayed on the general interface, the screen will automatically switch to the display time after 8 seconds. The initial time is 12:00 at noon on the 24-hour clock. The initial date is 1 day. month; 2. Press and hold for 2 seconds to enter the time setting state, set the hour, minute, month and day. When there is no button for 8 seconds, it will automatically exit the setting interface. SET button: 1. Increase the value when setting the time, date, and ALM. Press and hold the button to have the fast up function; 2. On the time/date interface, set the on/off alarm and snooze function, set in the following order: alarm → alarm, snooze (Zz) simultaneous ON → alarm, snooze and OFF at the same time (cycle switching ). SNOOZE key: In the case of Snooze (Zz), if the alarm goes off, press the SNOOZE button to turn on the snooze function (the snooze time is 8 minutes, the snooze time is unlimited, the snooze time is 1 minute; the alarm sounds Time, the alarm sign and Zz flashed together, only Zz was flashing while waiting for snooze.) ALARM button: 1. Press once to switch from the time/date interface to the ALM interface. Press and hold for 2 seconds to set the hour and minute of the alarm. As long as there is a setting, the alarm will be activated. 2. When the highest/lowest temperature and the corresponding humidity are displayed, press the ALM/CLEAR button to clear the displayed maximum/minimum temperature and relative humidity, and automatically return to the current temperature and relative humidity display mode after 3 seconds; ºC/ºF key: 1. On the interface displaying time, press to switch ºC/ºF; 2. On the interface displaying time, press and hold for 2 seconds to switch the 12/24 hour system; MAX/MIN key: Press MAX/MIN once to display the highest temperature and relative humidity display mode, press MAX/MIN once to display the lowest temperature and relative humidity display mode, then press MAX/MIN once to return to the current temperature and relative humidity display mode. In the MAX or MIN display mode, if there is no button for 8 seconds, it will automatically return to the current temperature and relative humidity display mode.