Hydrion Chlorine Test Paper provides a simple, reliable, and economical means to measure the concentration of free available chlorine in sanitizing solutions. With color matches at 10-50-100-200ppm, the test paper measures concentrations between 10-200ppm. 15-foot roll of test paper and matching color chart. A simple, reliable way to meet Federal, State and local food safety guidelines. Trusted by health agencies around the world for mandatory sanitizer testing. Instant, accurate results. Made in the USA.