Features: Suitable for testing and analyzing residual chlorine, pH, total alkalinity, hardness, iron, copper, lead, nitrate, nitrite, bromine, total chorine, cyanuric acid, chromium/Cr, fluoride. Easy to test.Fast, easy and accurate in use. How to use: 1. Collect water sample to be tested in a vial, cup or container. 2. Immerse the test strip in the desired water sample and remove within 1-2 seconds. 3. Hold the strip horizontally and gently tap or shake to remove excess water. Take extra precaution to ensure that the water from the test pads don't bleed into each other. 4. Read the test results carefully within 60 seconds in a good light and with the test area held near the color chart on the bottle label. Changes in color that appear along the edges of the test pads or after moving more than 2 minutes have passed are of no significance. Specification: Type: W-14 Water Test Strips Size: 55 x 55 x 130mm(2.17 x 2.17 x 5.12in) Quantity:1Box(50Pcs/Box)