Very Easy to operate, quick testing, obvious results. Simplest and cheapest way to test water quality. Buy for yourself and check the condition of your drinking water. The electronic color tester is an effective tool that visually demonstrates the difference between high TDS water and low TDS water. Features: Easy to operate and provides fast, clear results. Provides a simple method to test water quality. Helps users assess the purity level of drinking water. High precision. Testing methods: Prepare two transparent cups of water (100 to 150 ml), one with tap water and the other with RO water. Insert the metal rods into both cups, turn the device on, and begin the test. After 30 to 60 seconds, turn it off and remove the electrolyzer. Caution: Avoid electric shock during use. Do not touch the rods when the device is plugged in. Testing Analysis Results: Black: Heavy metals Yellow: Dissolved acids, fluoride, and organic matter Green: Arsenic, mercury, lead, copper, sodium Blue: Bacteria, viruses, carcinogens, chemical fertilizers, pesticides, etc. Red: Iron, rust, and bacteria White: Lead, zinc, mercury, inorganic impurities Specifications: Plug: EU Plug Voltage: 220V Power cord length: 85 cm Iron bars length: 7 cm Size: 10.2 x 3.7 cm Quantity: 1 Piece Note: 1. Transition: 1 cm = 10 mm = 0.39 inch 2. Please allow 0–3 cm error due to manual measurement. Ensure you are comfortable with this before purchasing. 3. Due to differences in monitor displays, the image may not reflect the actual item color. Thank you! No retail packaging included. Package Contents: 1 x Water Quality Testing Device