Check the listing for details. 4 x PH Test Strips 3.8-5.4 320 Indicator Papers Litmus Tester Water Testing. Condition: New. Listed at 12.81 USD. Litmus papers are used to determine the pH level of a liquid and determine if a solution is acidic, basic, or neutral. Widely used for industrial chemical testing, science education, laboratory use, drinking water, swimming pool, spas, aquariums, and classroom analytical chemistry.SpecificationAccuracy: 0.3 pHTesting Range: 3.8-5.4Testing Paper Size: 54mmx9mm (L*W)Overall Size: 70mmx45mmx5mm (L*W*H)Packing List: 4 x Litmus Test Kit (80/Pack,320pcs)AdvantageThere are 8 color-coded scales that go from 3.8 to 5.4. Also can be used to determine the strength of acid and base, as we go from 5.4 to 3.8 the acidity of the solution increases.InstructionDipping the pH paper into a solution and observing the change in color of the paper. After one second, compare it with the standard color cards and read the pH value.