Direct from the Manufacturer - USA SenSafe Total Chlorine #480010 CONTAINS 1 BOTTLE OF SenSafe Total Chlorine Water Check makes testing for Total Chlorine quicker, easier, and more reliable than ever. There are no powders or tablets to mix, no technical training is required, and no hazardous chemicals are used. Get accurate results in as little as 1 minute. Simply dip the test strip into your sample according to the instructions provided, remove excess water, wait, and read your results using the color matching guide. It’s that simple. Comes with instructions for two testing methods. Method A Detects: 0. 0, 0. 1, 0. 2, 0. 5, 0. 8, 4. 0, 10. 0 ppm (mg/L). Method B Detects: 0. 0, 0. 05, 0. 1, 0. 15, 0. 2, 0. 5, 1. 0 ppm (mg/L). Note: Temperature compensation chart available upon request for hot or cold water testing. Contact ITS at its@sensafe.