Feature 1Manual Calibration: Pen Handheld design, manual calibration with screwdriver. 2High Accuracy: Displaying clear, large and easy to read numbers will be especially helpful for visually impaired people. 3Portable: Small in size and light in weight, just like a pen, it is convenient for you to take it with you when you go out. 4Applicability: Suitable for aquarium, food processing, laboratory, paper industry, swimming pool and school use. 5Water Quality EC Meter: Measurement range: 0~1999s/cm; resolution: 1s/cm; accuracy: 2% FS.Item Type:WaterQualityTesterMaterial: ABSMeasuring Range: 0~1999s/cmResolution: 1s/cmAccuracy: 2% F-SWorking Environment: 0~50Automatic Temperature Compensation: 0~50Battery: AG13 x 4 (Battery Not Included)Application: Water Quality DetectorWeight: Approx.125g / 4.4oz .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x Water Quality Detector1 x Screwdriver1 x User Manual1 x Box