Specifications: Can detect various impurities in water, such as magnesium ions, calcium ions and heavy metal ions. Once you have this tester, you can clearly know how the water quality is in the home. It can be used with one click, very convenient and practical. Instructions: 1. Take off the cap and turn on the on/off switch. 2. Put the pen into the solution to be tested, the height of the solution should not exceed 4cm (starting from the pen end). 3. Gently stir the pen in the solution to be tested, and wait for the reading to stabilize. 4. After use, wipe the water in the tip of the pen with a cloth and cover the pen back. Item Name: Water Quality Tester Material: ABS Battery: 2 Button Batteries (Included) Impurities: Soluble Salts, Ionic Organic Matter, Heavy Metal Features: Portable, Lightweight, Sensitive Probe Length: 13.5cm/5.31" (Approx.) Diameter: 1.2cm/0.47" (Approx.) Notes: Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Water Quality Tester