The Ozone Test Kit was designed to measure the Ozone level in pool or spa water. The test kit includes unit-dose, foil packaged TesTabs® tablet reagents for 20 tests along with a test tube and a ColoRuler. The ColoRuler color chart allows the user to measure Ozone from 0.01, 0.025, 0.05 and 0.10 ppm.