These pH Test Strips are perfect for a variety of uses; whether you're conducing a science experiment or testing your pool water or your favorite beverage, they provide an accurate reading every time. They measure the entire pH range from 1-14 in 1.0 units. Whether you're a beginner or an expert, these strips are the perfect way to test the acidity or alkalinity of any liquid. Each zip seal bag contains 50 pH test papers and a colorimetric chart printed on a waterproof label. Only a small indicator test pad at one end of each strip undergoes a color change, making it easy to keep fingers out of the way when dipping in solution and reading against the color chart. Strips measure 64mm long and 5mm wide.