Oreq TS821DB No.2 Phenol Red Test Solution for Dual Test Kit, 1/2-Ounce Phenol red test solution is use for dual test kit This solution is used to test the chlorine or bromine levels in pool water These test solutions provide quick and easy pool and spa water analysis for residential pool owners Keep away from heat and store in sealed container Comes in 1-1/2-ounce container. This is a pack of 1