Features: It is compact, easy to carry and has a delicate appearance. It can be used in swimming pools, hot springs, spas, any water you want to test. Its measurement is accurate and you can use it safely.It will be your preferred water quality test. Here is a simple, portable dual-use box containing PH and residual chlorine test fluids, as well as the corresponding colorimetric. The operation is simple, you only need to spend a little time to complete the test, and get the test results quickly. The Numbers on the color card are clear and easy to see. You only need to use your hands and your eyes. Specifications: Condition:100% Brand New Material: Liquid wastes Color: As shown in the picture Size: Box: Approx.15cm/5.9in(L) Application: Residual chlorine and PH test. The ideal range of residual chlorine in the pool water is 1.0-1.5 ppm; the ideal range for the pH of the pool water is 7.2-7.6. Usage: Residual chlorine: Rinse the colorimetric tube with water to be tested and fill it into the scale. Add 3 drops of residual chlorine reagent, cover the lid and shake it several times to compare the residual chlorine color card reading. PH: Rinse the colorimetric tube with the water to be tested and fill it into the mark. Add 3 drops of pH reagent, cover the lid and shake it upside down several times to compare the pH card readings. Package List: 1*Swimming Pool Water Test Box 1*PH Reagent 1*OTO Reagent 1*Test Bottle Set Note: When testing pH, if the residual chlorine content is higher than 3.0 ppm, you may get a wrong pH test result. In this case, reduce the residual chlorine content of the pool water before doing any other tests. Warning: Store in a place that is out of reach of children. Harmful if swallowed, may cause burning, store in a cool and dark place. In each beginning season, please use new solution to maintain accuracy. Please be at a depth of 40 cm below the water surface to take a water sample.