Feature:1. Reasonable design, pen end electrode can be directly inserted into the tank water to measure, the pen sleeve can be used as a container of the measured liquid, very convenient to use.2. Rapid measurement, due to the exquisite naked sensor element, 5-30 seconds to complete a measurement, at any time to observe the water quality of the tank.3. Easy to clean, the electrode sheath can be removed, easy to clean the probe and sheath.4. An ideal tool for aquarium, fish tank, etc.5. Temperature compensation, automatic conversion into 25 Celsius TDS value.Specification:Condition: 100% Brand NewMaterial: ABSItem Type: Water Quality Test MeterMeasuring range: 0～9999mg/LResolution Ratio: 1 mg/LAccuracy: ±2%（F.S）Working Temperature: 0～50℃battery model: quantity: Button Cell AG13*2(160mAh) (Not Included)Automatic Temperature Compensation:The indicated value can be automatically converted to the value at 25℃.operating steps:1. Take off the sleeve2. Light Touch, ON/OFF switch, plug in.3. Insert the TDS pen into the tested solution until the liquid is slightly below the immersion line.4. Gently shake the instrument and read after the display value is stabilized.5. After use, press ON/OFF, turn OFF the power, clean the electrode with distilled water , and put ON the protective sleeve.Package List:1x Test Pen1x Manual