Feature: 1. Multi Functional Water Quality Testing: It can measure PH value, ORP value and monitor free chlorine content, applicable to different water quality environments. 2. High Accuracy Measurement: This water quality test pen is highly accurate and provides reliable analysis of water quality status. 3. Swimming Pool Water Quality Monitoring: It can be used for swimming pool water quality testing to ensure the safety and cleanliness of swimming pool water. 4. Essential for Mariculture: Can test salinity, suitable for mariculture industry, help to maintain the ecological balance of seawater. 5. Easy to Carry and Use: Portable design, easy to operate, convenient for users to use in different scenarios. Specification: Item Type: Water Quality Testing Pen Weight: 400g / 14.11oz Material: ABS FAC: 0.1-4.0ppm PH: 0.1-14.0рH ORP: ±1200mV Temperature: 0.1-60.0°C; 32.0-140°F Salinity: 0.01%-25.00%, 0-10000ppm, 10.1-200.0ppt TDS: 0-10000ppm, 10.1-200.0ppt EC: 0-10000us/cm, 10.01-19.99ms/cm, 20.1-400.0ms/cm Waterproof: IP67 Battery: 4 x 1.5V (LR44) button battery (shipped without battery) Product Size: Approx. 18.3x4.2x4.2cm / 7.2x1.7x1.7in Display: LCD display Temperature: Automatic temperature compensation 0-60°C Data: Retention Auto Shut Off: 5 minutes Widely Used: In drinking water, sewage treatment, water purification, fish tank culture, swimming pool, hydroponics, medical treatment, etc. . Package List: 1 x Testing Pen1 x Calibration Fluid1 x Instruction Manual Note: Note that electrodes should be thoroughly cleaned after use.