100% Brand New. High accuracy pH test paper, pH range from 1-14 pH 1-14 color chart in each pack There is a strong correlation between the pH of the body's internal environment and pH paper help you to maintain good healthy body by testing many usual everyday substances, including moisturized soap, lemon juice, milk, liquid detergent, moisturized soil, saliva, urine, sweat...etc. The test strip color changes must be matched with the pH scale color chart within about 15 seconds. Instruction: Simply press the testing strip to the object or liquid you are testing. Half second later, take out the paper and using the color chart included, compare the color change of the paper to find out the acidity level of your testing subject. Can not indicate the Acid or alkali solution when its density was lower than 0.01%. Keep dry for the rest paper. Included: 1 x Set of 80pcs pH paper test