Function: Compact, easy to carry, delicate appearance. It can be used in the pool, spa, hot spa, or any water you want to test. Measurement is accurate and safe to use. You can test your desired water quality. This is a simple, portable dual use box that includes PH and chlorine residual test fluid and corresponding color analysis. Easy to operate, just spend a little time completing the test and get the test results quickly. The numbers on the color cards are clear and easy to read. Just use your hands and eyes. Specifications: Condition: 100% Brand New Material: Waste Liquid Color: As Picture Size: Box: Approx 15cm / 5.9in (L) Application: Residual Chlorine and PH test. The ideal range of residual chlorine in pool water is between 1.0 and 1.5 ppm. Ideal range of pool water pH is 7.2 to 7.6. Usage: Residual Chlorine: Rinse the color tube with water to test and fill the scale. Add 3 drops of residual chlorine reagent, cover the lid and shake several times to compare the remaining chlorine color card readings. PH: Rinse with water to test the color metering tube and fill in the mark. Add 3 drops of pH reagent, cover the lid, shake it up and down several times to compare the readings of the pH card.