The 10 Books per pack (Each book contain 20 Papers). High accuracy pH test paper, pH range from 1-14.
The pH color chart with each book The test strip color changes must be matched with the pH scale color chart within about 15 seconds
Can be used to measure pH of water, hydroponic nutrient solution, soap, lemon juice, vinegar, milk, liquid detergent, moisturized soil, saliva, urine, sweat.