This hydrion double roll dispenser holds two 15 ft rolls of pH paper with a wide range of pH 4-9. The dispenser is constructed of polystyrene with stainless steel cut off lips. This wide range paper has a sharp color change for each full pH unit. The pH color chart is printed on the side of the case. Range: 4-9. 2 Rolls/Dispenser. Micro Essential Lab 151.