* Display Indoor temperaturer and humidity,Outdoor temperature;
* Record the maximum and minimum temperature and humidity;
* Deg C and deg F switch;                              
* Freeze from -1C to +4C;
* Temperature measure range:
                     Indoor: -10~+50C (+14~+122F )
                     Outdoor: -50~+70C (-58~+158F )
* Humidity measure range: 20~99% RH;      
* Accuracy: +/-1C,+/-5% RH;    
* Use of the environment: -10~+50C
* 1.5V operate ( AA );