15cc vial of pH Reagent drops for testing pH of water. The kit comes with pH color chart. Simply add 2-3 drops into small amount of water. Shake and observe color change, compare to the pH chart to determine pH.
Variant: pH reagent drops for frequent testing pH of water in larger 50cc glass bottle. Label features pH color chart. Simply add 2-3 drops into small amount of water. Shake or swirl and observe color change.