The AquaChek TruTest Digital Test Strips Reader combines the AquaChek test strips with advanced digital technology to measure your water levels easily and accurately. It tests for Free Chlorine/Bromine, pH and Total Alkalinity and provides you with low ok, or high indicators for each test parameter. All you have to do is dip one of the disposable test strips into your pool or spa, insert it into the reader and you get accurate results in seconds. It even stores the last 9 test results, so keeping track of your levels is a cinch! 25 strips are included with meter purchase. Power source: 2AA alkaline batteries (not included).