Universal indicator color chart cards are used to determine the pH of a solution. These handy smaller chart cards display the colors and pH values an indicator would create for each pH unit from 3 to 10. The charts are also available as a laminated 8 1/2? x 11? Color Chart (IS5097) and 8 1/2? x 11? Overhead Transparency Color Chart (IS5098). Pack of 30 Universal Indicator pH Color Charts Cards For use with: IS30000 Universal Indicator Solution 500 mL IS30002 Universal Indicator Solution 25 mL DOT Info: Non-regulated