At the cost of just a few rolls of litmus paper, you can have the industry's best pocket-size pH tester. The Checker® supplies you with fast and accurate readings from 0.00 to 14.00 pH with a resolution of 0.01 pH. This compact tester features a large easy-to-read LCD and a simple to perform 2-point calibration. The pH electrode of the Checker® can be replaced; simply unscrew the electrode from the meter body and screw on a new one. The Checker® is fast, accurate, lightweight and with 3000 hours of battery life, you don't have to worry about frequent battery replacement. Testing pH has never been easier!