Check the listing for details. 5Pcs/400 Strips PH 5.5-9.0 PH Test Strips w 5Pcs Test Droppers Yellow. Condition: New. Listed at 12.71 USD. Litmus papers are used to determine the pH level of a liquid and determine if a solution is acidic. Widely used for industrial chemical testing, science education, laboratory use, drinking water, aquariums, and classroom analytical chemistry.SpecificationColor: YellowDropper Length: 135 mm / 5.3 inchTesting Paper Size: 60 x 9 mm / 2.4 x 0.4 inch (L*W)Test Range: PH 5.5-9.0Packing List: 1 Set - 5 x PH Test Strips with 5 x Test Droppers (80 strips each pack, total 400 strips)Advantage1. It is Portable and easy to store which can be used to determine the strength of acid and base conveniently. Sensitive to the environment and temperature changes.2. Each package comes with a color chart, and different pH values can correspond to specific colors.3. Comes with droppers, so you can draw the volume of the solution according to your need.