Features: Compact and pocket-sized designEasy to use and provides a quick measurement.High accuracy with 2% full scale accuracyData hold function and built with Automatic Temperature Compensation (ATC)Auto power off.Wide range of applications in water quality testingPre-calibrated at factory.Supplied with a screw driver for calibration if necessarySpecifications: LCD display: 4 digitsMeasure Range: 0 ~ 19.99 ms/cmResolution: 0.01 ms/cmAccuracy: 2% F.S. (Full scale)Automatic Temperature Compensation (ATC): 0 ~ 50 C (32 ~ 122 F)Operating Temperature: 0 ~ 50 C (32 ~ 122 F)Power Supply: 2pcs x CR1632 button cell batteries (not included)Material: plasticcolour: bluePackage Contents: 1 x water test pen1 x screw driver1 x English manualOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.