Functions: * high precision temperature and humidity detection

* temperature (℃/℉ unit) testing range: -20℃ ~ +70℃, tolerance: ±0.5℃

* humidity testing range: 10% ~ 99%, tolerance: ±2%

* MAX/MIN value recording function

* temperature and humidity locking function

* LCD screen display with LED backlight

* automatic shutdown when there's no button operation in 3 minutes