Equipped with light If it is mineral water , the light will be on , otherwise it will not be on Suitable for water such as energy water machines , functional water machines , ionized water machines , ultrafiltration water purifiers , RO water purifiers , alkaline or mineralized , energy cups , , to check whether it is qualified High-precision copper probe , the result is more accurate , and the speed is faster BIO energy detection pen , which can quickly discriminate pure water , mineral water , and energy water Gently immerse the pen tip in the water sample and observe the indication Remember not to wet the main body of the pen, Manufacturer: Watreketal