Insta-Test 4 Chlorine Test Strips are the easy way to check your waters chemical balance this season to ensure safe and clean swimming water for yourself and your guests. These strips will check your pool waters Free Chlorine, Alkalinity, Cyanuric Acid (stabilizer) and pH in just a matter of seconds! These test strips are specifically designed for swimming pool water and come in a pack of 50 so you can always make sure you’re water is safe to swim in. The convenient close cap bottle top allows you to secure the strips so they don’t wet get. With these strips, it’s as easy as dip and read!