These Hydrion Chlorine Indicator Strips provide a quick and reliable way to measure free chlorine levels from 0 to 300 parts per million (ppm). Each vial contains 100 test strips featuring a clear color chart for easy reading of results. Perfect for testing swimming pools, spa water, sanitizing solutions, and other applications where chlorine monitoring is essential. The strips deliver results in seconds - simply dip, remove, and compare to the color chart on the bottle. The convenient vial packaging keeps strips protected and ready for use. With precise gradients at 0, 25, 50, 100, 200, and 300 ppm, these professional-grade test strips help maintain proper chlorine levels for optimal sanitization. The compact size makes it easy to store and transport wherever testing is needed.