Features:
1) It can receive the signal of three sensor units, and display them on the
    screen, the distance about 30m in the open field
2) Measure the indoor temperature and humidity
3) Measure range: -10 ~ 60°C or 14 ~ 140°F; 20%RH ~ 80%RH
4) Accuracy: ±1°C or ±2F, ±5%RH
5) Display date, time and time alarm
6) Max./min. indoor temperature and humidity memory
7) Back light
8) Weather prediction
9) Celsius and Fahrenheit switch 

Specifications: 
1) Size of the product: 142 x 80 x 31mm
2) Screen size: 53 x 44mm
3) Eight keys: ADD, code, C/F, max./min., SUB/CLR, alarm, clock, light
4) Three LR6 AM3 AA/1.5V alkaline batteries
5) Light color: green

Accessory unit (sensor):
1) They can send the signal to the main unit
2) Measure the outdoor temperature: 
    a) Measure range: -20 ~ 70°C or -4 ~ 148°F
    b) Accuracy: ±1°C or ±2°F
3) Max./min. outdoor temperature memory
4) Celsius and Fahrenheit switch
5) Waterproof
6) It can be hanged on the wall or put on the table 
 
Specifications: 
1) Size of the product: 95 x 62 x 23mm
2) Screen size: 25 x 12mm
3) Three keys: code, C/F, max./min.
4) Two LR03 AM4 AAA / 1.5V alkaline batteries