Feature: 1. The test pen can measure four parameters: total dissolved solids (TDS), electrical conductivity (EC), PH, and temperature. 2. The test pen has high performance, fast measurement, high accuracy and high stability. 3. The water quality test pen adopts ergonomic design, which is light and portable, and easy to use. 4. Multi‑function detection mode, simple and convenient function switching and a large LCD screen for easy and clear reading. 5. The water quality tester is suitable for water sources, aquarium, hydroponics, hot springs, swimming pools and other water systems. Specification: Item Type: Water Quality Test Pen Material: Plastic Weight: Approx. 155g / 5.5oz Battery Attributes: 3 x 1.5V Button Battery LR44 (Battery Not Included) Technical Index: Range: PH: 0.00-14.00 PH EC: 0-19990us/cm 0-19.9ms/cm TDS: 0-19990ppm 0-19.9ppt Temperature: 0°C-50°C (32°F-122°F) Resolution: pH: 0.01PH EC: 1us / cm (<1999us / cm) 10us / cm (> 1999us / cm) 0.1 ms/cm TDS: 1 ppm (<1999 ppm) 10ppm (> 1999ppm) 0.1pptTemperature 0.1°C (0.2°F) Accuracy: PH: ±0.03 pH EC, TDS: ±2%F.S Temperature: ±1℃ Temperature Compensation: 0°C-50°C Working Temperature: 0°C-50°C Applicable Scenarios: suitable for water sources, aquariums, hydroponics, hot springs, swimming pools and other water systems. How to Use: After Installing the battery, open the cover and put the measuring head into the liquid to be measured, and the value can be displayed in a moment.. Package List: 1 x Water Quality Test Pen (Battery Not Included)1 x Manual1 x Screwdriver1 x Protective Shell