What You Get: The package contains 5 packs of pH test paper. Each pack contains 80 pieces, 400 pieces in total, sufficient quantity for long-term use and to meet various needs. Lightweight and Portable: Each piece measures approximately 5 x 1 cm, offering a compact and lightweight design for easy carrying and storage. Please note that the test strips must be stored in a dark and dry place. pH 1-14 Range: The scale ranges from 1 to 14, where 1-6 indicates acidity, 7 is neutral, and 8-14 indicates alkalinity. The color change on the test strip should be compared to the pH color chart within approximately 15 seconds. Application: The test paper will show a color change within seconds when in contact with a solution. Remove a test strip and compare the result to the standard color chart on the packaging. Lower numbers indicate stronger acidity, while higher numbers indicate stronger alkalinity. Usage: These universal pH 1-14 test paper strips can be used to test water, swimming pools, fish tanks, soil, milk, and detergent, among other common substances.