1[LCD BACKLIGHT DISPLAY] Portable ORP meter with LCD backlight display, it only takes a few seconds to read the readings on the digital display. 2[HIGH RESOLUTION] The measurement range is 19991999mV, the resolution is 1mV, the accuracy is 5mV, and 050 automatic temperature compensation. 3[HOW TO USE] Just immerse the probe of the ORP testing pen in the water to quickly detect the redox potential value of the water. 4[QUICK AND SIMPLE] This is a very useful tool when you need to test the water quality of pond, aquariums, swimming pools, aquaculture, spas, etc. 5[SMALL AND PORTABLE] ORP test meter, mini size, light weight, compact structure, high measurement accuracy, easy to use, high stability and reliability. Item Type: ORP TesterMaterial: Plastic Weight: Approx. 162g / 5.7oz Length: Approx. 17.2cm / 6.8in Measuring Range: -1999-1999mV Resolution: 1mV Accuracy: 5mV Working Environment: 0-50; RH 95% Automatic Temperature Compensation: 0-50 Battery: 4 x 1.5V LR44 (AG13) (Battery Not Included) Application Areas: Aquaculture, industry and agriculture, environmental protection, food manufacturing, water purification, swimming pools, aquariums, fish hatcheries, food processing, laboratories, paper industry, etc. 1 x ORP Tester (Battery Not Included) 1 x Screwdriver 1 x Manual 1 x Storage Box 1. Please allow 0& 8209;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.