Features: Gently immerse the pen tip in the water sample and observe the indication status. Remember not to wet the main body of the pen. High-quality BIO energy detection pen, which can quickly discriminate pure water, mineral water, and energy water. Equipped with indicator light. If it is mineral water, the light will be on, otherwise it will not be on. High-precision copper probe, the test result is more accurate, and the test speed is faster. Suitable for test healthy water such as energy water machines, functional water machines, ionized water machines, ultrafiltration water purifiers, RO water purifiers, alkaline or mineralized filters, energy cups, etc., to check whether it is qualified. Specifications: Material: Plastic Size: approx124x18mm/4.88x0.7in Package Includes: 1x Water Quality Tester note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.