Ondilo ICO for salt electrolysis pools (yellow ORP sensor with gold contacts / optimized gold measuring cell for salt water) instead of orange (standard platinum measuring cell). WiFi pool thermometer and pool tester in one. Measures pH, water temperature, ORP/redox (chlorine) and conductivity / TDS (salt content / water hardness) in your swimming pool. ICO can also be operated in the skimmer and fits under pool covers. This model is suitable for water treatment using salt electrolysis.