Red Litmus Test Paper, foolproof pH test to determine base, Test strip will turn blue if dipped into an alkaline solution (pH >7), Pocket-sized, lightweight vial, No color chart necessary, solution must be water-based
Insta-TEST* pH Wide Range Test Strips, Applications: Drinking Water, Industrial Water Boiling and Cooling, Laundry and Sanitation, Water and Wastewater. 50 strips/vial.