With distinct color PH scale for result comparisons. The test strip color changes must be matched with the pH scale color chart within about 15 seconds. Quick and easy to use. Provides reliable and accurate pH readings. Easy to carry. Appropriate for testing alkaline or acid level of any liquid. Great product to have in every lab and at home to measure and inspect water quality, urine, saliva, soil, alkaline diet, aquariums etc. Scale Reads From 0 to 14: 0 - 3 indicates a very acidic substance 4 - 6 indicates an acidic substance 7 indicates neutral 8 - 11 indicates alkalinity 12 - 14 indicates a very high level of alkalinity Total length:approx. 500x1.3mm PH range: 0-14 Usage: Take out a test paper. The 2 color blocks all immersed in the liquid. After 1 seconds to take out, in contrast to the color of the color reading value in 30 seconds. Note:Due to different production batches, there are differences in printing/appearance, which does not affect use. Colour:As Shown Material:Plastic Package Contents: 2 x PH Meter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.