Feature: 1. Made of high quality ABS material, it is durable, wear-resistant, corrosion-resistant and can be used for a long time. 2. Equipped with high-precision sensor, it is sensitive in response and accurate in measurement results, and widely used in industry and laboratory. 3. With LCD backlight display, the measurement results can be directly displayed on the screen, convenient for observation. 4. This product is mainly used to measure the level of ORP and observe the trend of obtaining or losing electrons. 5. Small size, compact structure, easy to carry, suitable for aquarium, hydroponics, hot spring, swimming pool and other water systems. Specification: Condition: 100% Brand New Item Type: Water Quality Tester Material: ABS Test Range: 0 - ±1999mV Resolution: 1MV Accuracy: +-5MV Operating Temperature: 0°C -50°C Battery: 2 x 3 V Button Battery (CR1632) (Battery Not Included) Weight: Approx. 97g / 3.4oz Size: Approx. 147x27x8mm / 5.8x1.1x0.3in Package List: 1 x Water Quality Tester (Battery Not Included)1 x Instruction Manual1 x Screwdriver Note: 1.Please allow 0-1 inch error due to manual measurement. Thanks for your understanding.2.Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.