There is a strong correlation between the pH of the bodys internal environment and pH paper help you to maintain good healthy body by testing many usual everyday substances. The scale reads from 1 to 14: 1 - 3 indicates a very acidic substance； 4 - 6 indicates an acidic substance； 7 indicates neutral； 8 - 11 indicates alkalinity； 12 - 14 indicate a very high level of alkalinity. ======== Package included: 160 × PH 0-14 Test Paper Strips