Possible measurements: 
-EC µS; mS  
-TDS ​​ppm; ppt
The instrument is supplied already calibrated with a solution at 1413 
Calibration solution: any 
Digital calibration system Auto-
off. Low battery indicator.
Large display with LCD screen and simultaneous temperature reading.  

Technical specifications:
 Measurement range:
-EC 0 - 9999 µS; 0 - 9.9 mS  
-TDS ​​0 - 5000 ppm; 0 - 5.0 ppt
Temperature range: 0 - 80 ° C; 32 - 176 ° F 
Resolution: 1 μS / ppm Temperature: 0.1 ° C / F Accuracy: +/- 2%

Power supply: 3 x 1,5V
Dimensions: 15.3 x 3.2 x 1.8 cm Weight: 53.9 gr

N.B. = COM80 does not contain pouches for calibration solution - See more at: https://www.indoorline.com/com80-conduttivimetro-professionale-micro-s-tds-temp-hm-digital.html#sthash.yD3CneS3.dpuf