The strip design takes into account different application scenarios such as commercial use and home use, and is an efficient and accurate method for testing chemical substances in water. The colorimetric method is used to test the total bromine, residual chlorine, pH value, and total alkalinity in water. It is simple, fast and accurate. The color chart is easy to read and will not fade over time. 1 bottle contains 50 test papers, and comes with 5 independent waterproof packaging, easy to carry and store, ensure long-term use. Made of high quality material, it's environmentally friendly and durable. Bottle length is 9.8cm, width is 3.7cm. It's very suitable forwater quality testing of swimming pools, hot spring pools, spas, household water, aquariums. Item Name: Water Quality Test Strips Material:Paper Storage Method: Recommend Dry And Ventilated to Storage Data Types: CI, PH, AlK, TH Size:9.8cmx3.7cmx3.7cm/3.86inx1.46inx1.46in Notes: It is recommended to use at room temperature, otherwise the results will be inaccurate. Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 50 X Water Quality Test Strips