For the rapid determination of pH values from 0-14. The Ultrafast test set consists of two 15-foot rolls of pH paper-the InstaChek 0-13 and the Ultra-Sharp 12.5-14 test papers. The Insta-Chek 0-13 is a general-purpose, immediate response, wide range paper with a different bright color for each pH value from 0-13. The Ultra-Sharp 12.5-14 test paper is ideal for determining high pH values. It exhibits crystal clear color changes, from a bright blue at 12, through green at 13, and finally to sunny yellow at 14. Used in tandem, these two papers span the entire pH scale from 0-14. Refill package contains five 15-foot rolls of the Insta-Chek 0-13.