Apera PCO60-Z Smart Multi-parameter Tester Kit is designed to simplify professional measurement of pH, conductivity/TDS/salinity/resistivity, and ORP (redox), suitable for general water solution applications e.g. pools and spas, hydroponics, water treatment, cooling towers, boiler water, food and beverage making, aquarium, aquaculture, environmental monitoring, educational purposes, etc. Connect the tester with your iPhone or Android phone in ZenTest mobile App (free download) to take full control of the entire measuring process.