This is essential so that you can measure the strength of the nutrient mix that you are giving your crops. 

Features
-Automatic to power On / Off. Automatic temperature compensation function. Long service life (platinum sensor).
-Moisture proof, waterproof and heat resistant.
-Measure EC, CF and PPM scales. High electrical conductivity, can be measured for a wide variety of crops.


Specifications:
Color: As shown of picture
Size: about 41cm/16.14''

Measuring Range:
0.4 ~ 5.2EC
4 - 52CF
280 ~ 3640ppm ; (EC × 700)
200 ~ 3000ppm ; (EC × 500)

Resolution:
0.1 EC
1 CF
70ppm ; 700
50ppm ; 500

Accuracy: ±4% of reading
Temperature Compensation: Automatic
Operating Temperature: 0 ~ 50 °C (32 ~ 122 °F)
Calibration: Factory Calibrated
Power Source: 3 x 1.5V (AA Batteries)
Auto Sense: Aotu On and Aotu Off


Package Included:
1 x Nutrient Meter