The High Level Chlorine test strip tests levels of free chlorine in a solution, in steps of 0-50-100-250-500-1,000ppm, giving results in just seconds. The High Level Chlorine test strip can be used in facilities where food preparation areas, equipment, and general disinfection are more strictly controlled. The higher range provides a much higher degree of certainty that all organisms are either killed or rendered ineffective. The vial contains 100 test strips.