Features: Testing drinking water purity to ensure it's healthy. Visually demonstrates the difference between high TDS water and low TDS water. Simple to operate with quick testing to get obvious results. Suitable for pure water production and drinking, tap water, well water, sea water, fish for tank water. A unique gift to keep your family from dirty water and keep healthy. Specifications: Material: ABS+Metal Body Size: 100x70x42x30mm/3.94x2.76x1.65x1.18in Cable Length: 800mm/31.5in Testing methods: Prepare two transparent cups of water (100 to 150 ml ) one cup holds tap water, the other cup holds RO water. Put metal pillar into two cups, turn ON and begin the test, After 30 to 60 seconds, turn it off and remove the water electrolyzer. Caution: Avoid the electric shock while using the devise; Do not for touch the rods once the precipitator is plugged into an electric outlet. Package Includes: 1X Electrolyzer 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.