Cheap: $5~10/pc Delivery: 1day Easy to use Safe Quick testing Water electrolyzer: Features:Color: ... : 110~220V.ACAdvantage: 1. Easy to operate 2. High precision 3. Convenient to carry Instruction:1. prepare 2cups of water ... , sodiumBlue: bacteria, viruses, carcinogens, chemical fertilizers, pesticides, etc.Red: Iron and rust, bacteriaWhite: lead, zinc, mercury, inorganic dirtBlack: heavy metal ...